The geotouristic attractiveness of the underground trails in Zabrze, Dąbrowa Górnicza and Tarnowskie Góry towns (Silesian Upland)

In Zabrze, Dąbrowa Górnicza and Tarnowskie Góry towns, seven underground tourist trails are located in historical mines. Four of them were developed in the central part of the Upper Silesian Coal Basin, two of which, at the “Królowa Luiza” (“Queen Louise”) Adit (comprising the former coal mine “Królowa Luiza” and the drainage Main Key Hereditary Adit remnant), and two others at the “Guido” Mine in Zabrze town. The next one was developed in the eastern part of the Upper Silesian Coal Basin, in a part of the “Sztygarka” Training Coal Mine in Dąbrowa Górnicza. Two other trails are located in Tarnowskie Góry town, in the border zone between the Upper Silesian Coal Basin and the Silesian-Kraków Monocline. These are the relics of the historical lead, zinc and silver ore mine, and the “Czarny Pstrąg” (“Black Trout”) drainage adit. The bituminous coal deposits are hosted in the Upper Carboniferous clastic formations, which fills the Upper Silesian Coal Basin. The metal ores are hosted in Middle Triassic dolomites, which belong to the southern margin of the Silesian-Kraków Monocline. The geotourism attractiveness of all these historical mines was demonstrated by selected annual statistical data of tourist attendance. In general, the interest in these facilities has been growing since decades, same as the popularity of industrial heritage in the Upper Silesia. These three towns have become very widely known in Poland and in the world.


Introduction
The history of mining in the central part of the Silesian Upland (www1; Fig. 1) is very long. Two main types of mineral resources were exploited: bituminous ("hard") coal and zinc, lead and silver ores. The bituminous coal mining has started in Zabrze town ( Fig. 1) in 1791 and has lasted until 1998. The "Królowa Luiza" ("Queen Louise") coal mine located in this town was the oldest one in the Silesian Upland (Dzięgiel, 2007;www1;Fig. 1). Bituimous coal was exploited in numerous locations, but most of these mines had to be closed in the 1990s because of exhaustion of reserves and environmental issues. In Dąbrowa Górnicza town ( Fig. 1), coal had been mined in the years 1865-1995(Ciepiela, 2007Bielecki, 2008). Metal ores were extracted in Tarnowskie Góry town (Fig. 1), in the 16 th century and again, between the 18 th and 20 th centuries, and their production has ceased in 1922 (Dzięgiel, 2008).
In recent years, all these underground trails were included into the Silesian Industrial Monuments Route and the European Route of Industrial Heritage (Czornik et al., 2011;Drobniak et al., 2020;www5;www6). The Annual Fest of the Silesian Industrial Monuments Route, called "Industriada", jointly celebrated in all these sites, represents a great part of the Silesian Industrial Monuments promotion (www6). Hence, these trails have become very popular in Poland and in the world.  Bukowy et al., 1974) Geotourism vol. 17, 1-2 (60-61) 2020 https://journals.agh.edu.pl/geotour The aim of this article is to indicate the geotourism attractiveness of these objects. The criterion, chosen for the analysis, is the number of tourists visiting each of described attractions.

Methodology
The research was carried on using the direct field observations and the photographic documentation run personally by the author at the described sites. Apart from that, some papers and statistics from the Polish databank were reviewed for obtaining the statistical data of tourists visits at the described sites.

Geographical and geological settings of the central part of the Silesian Upland
The three towns: Zabrze, Dąbrowa Górnicza and Tarnowskie Góry are located in the central part of the Silesian Upland (Kondracki, 2011). Moreover, Zabrze is situated in the western part of the Upper Silesian Coal Basin (USCB), Dąbrowa Górnicza -in its eastern part and Tarnowskie Góry -in the border zone between the USCB and the Silesian-Kraków Monocline (Bukowy, 1974;Jurecz ka et al., 2005; Fig. 1). The USCB area is built of Upper Carboniferous sediments, which crop out in its central part. In the northern margin of the USCB, these strata are covered with Triassic sediments, which belong to the geological unit named the "Silesian-Kraków Monocline". In that area, some patches of Quaternary sediments occur, as well (Fig. 2).

Stratigraphy
Series Beds Lithology and thickness The area around Tarnowskie Góry town is built mainly of Middle Triassic sediments hosting metal ore deposits (Tab. 1; Fig. 2C). The ore-bearing dolomite is the host rock to lead and zinc minerals. Galena (PbS) is the most common lead mineral occurring in the Silesian Upland and the carrier of silver admixtures, especially in the Tarnowskie Góry ore deposits (Gabzdyl, 1999;Tab. 1;Fig. 2C). In general, the carbonate rocks around Tarnowskie Góry town are strongly karstified (Żero, 1968;Wilanowski & Lewandowski, 2016).

Historical coal mining in Zabrze town
In Zabrze, some parts of the two historical mines have been opened for tourists and have become geotourism attractions: the "Królowa Luiza" Adit and the "Guido" Mine (Drobniak et al., 2020;Gola, 2020;www3;www6;Fig. 2A).
The "Królowa Luiza" Mine has been developed in 1791 due to high demand for coal from the intensively growing Upper Silesian metallurgical industry. First ironworks have started operations in 1784, in Strzybnica, which is now a district of Tarnowskie Góry town (Dzięgiel, 2007;Gola, 2020). Bituminous coal seams were extracted in a number of surface excavations and underground workings. The shafts were sunk down to the depths from 30 to 800 m below surface.
For the first time the "Królowa Luiza" Mine had been opened to the public in the years 1965-1979. Visitors could observe the operation of mechanized longwall, located close to the Carnall Shaft (www4; Fig. 3). This industrial tourism attraction was managed by the Intercompany Mining Branch of the Polish Tourist and Country-Lovers' Association. Over 10,000 tourists a year visited the mine in that period. However, in 1979, it had to be closed to the public because of some mine safety problems (www4).
In 1998, the mine has halted production because of reserves exhaustion. However, as early as in the late 1980s, in its inactive parts located around the "Wilhelmina" and the "Carnall" shafts ( Fig. 3), the Coal Mining Museum in Zabrze has established one of its branches named "The Królowa Luiza Mining Open-Air Museum" comprising selected mine workings. It has been available to the visitors since 1993 (Dzięgiel, 2007;Żurek et al., 2010;Frużyński, 2012;Gola, 2020). Currently, this trail is called the "Family Route" of the "Królowa Luiza" Adit (Gola, 2020;www4;Fig. 3).
Since 2018, "The Queen Louise Mining Open-Air Museum" has been integrated with the final section of the old Main Key Hereditary Adit (Jurkiewicz, 2002;Jurkiewicz et al., 2009). This is an underground tunnel, which development had lasted from 1799 to 1863. Its task was to drain the coal mines "Królowa Luiza" in Zabrze and "Król" ("King") in Chorzów, and the other, neighbouring ones, as well as to transport the coal from the "Królowa Luiza" to the steelworks in Gliwice town through the Kłodnica Canal. Unfortunately, the growth of mining industry and the progress in water-pumping technologies, together with the exhaustion of shallow coal deposits contributed to relatively quick decline of the importance of this adit. It finally stopped operation in 1953. In order to regain the adit for tourists, the Society for the Restoration and Promotion of the "Królowa Luiza" Adit in Zabrze, "Pro Futuro", has been established in 2000 (Gałązka-Salamon, 2012). Local authorities of Zabrze town implemented a consistent promotion strategy based on principles of the industrial heritage tourism. Therefore, they decided to revitalize and adapt for tourism the final section of the Main Key Hereditary Adit and to connect it with the "Królowa Luiza" old underground workings (Jurkiewicz et al., 2009;Żurek et al., 2010;Bugaj & Glosz, 2012;Gola, 2020). Thus, since 2018 the "Królowa Luiza" Adit has been the site of two underground tourist trails: the "Water Route" and the "Family Route" (Figs. 3, 4A-4D) (Gola, 2020;www3).
The "Water Route" (www7; Fig. 3) is one of the most amazing underground tourist trails in Poland. The visitors pass its first section on foot through the original 19 th century drift, about 1 km long, cut 40 m below the surface. The drift is cut, entirely within the 6-m-thick coal seam No. 510 (in Polish coal seams identification system) belonging to the Upper Silesian Sandstone Series (Wilanowski et al., 2009;2015; Tab. 1). The visitors can observe a mining face worked in No. 510 coal seam, with roof support of the upper coal bench built of timber racks (Fig. 4A). The last section of the route, 1,130 m long, is a unique underground boat trip (Fig. 4B). It runs along the stone-lined, former Main Key Hereditary Adit illuminated by special lighting system and leads to the adit mouth located in the center of Zabrze (www3; Fig. 3).
The "Family Route" (www7; Fig. 3) is situated 35 m below surface and runs along a 1.5-km-long gallery. This is an extraordinary adventure, combining the observations of the authentic mine workings with the views of huge mining machines, and providing fun and educating experience for the youngest tourists. The visitors can examine the coal shearer operating along the long wall and protected by self-advancing supports (Fig. 4C). At the end of the trail, the visitors can travel with the historical underground train named "Karlik" (Fig. 4D), which carries them along some 1.5-km-long crosscut. The crosscut of that railway ride is lined with steel arches (Fig. 4D).
In the future, the third underground route in the "Królowa Luiza" Adit is to be opened to the public, connecting the "Carnall" and the "Wilhelmina" shafts ( Fig. 3; www4).
The "Guido" Mine ( Fig. 2A) has been in operation since 1855. It included a system of workings and shafts cut down to 300 m depth below surface. Coal was extracted until the 1930s. In 2007, the local authorities decided to open for tourism some selected old workings (Figs. 4E-4H) (Walerjański, 2008;Walerjański & Szczypkowska, 2010;Dzięgiel, 2011). Underground tourist trails are located at two former mining levels: 170 m and 320 m below surface (Frużyński, 2012;Piątek, 2013).
Geotourism vol. 17, 1-2 (60-61) 2020 https://journals.agh.edu.pl/geotour The tourist trail at the 170 m level enables the visitors to walk along the Ventilation Crosscut where they visit a 19 th century horse stable. Horses were used for pulling the hauling carts. The crosscuts are lined with wooden bars and steel arches (Fig. 4E). At the end of this crosscut, there are some rooms with the exhibition of old mining tools, lamps, rescue equipment and maps presenting traditional coal exploitaion systems. There is also a small geological museum and St. Barbara Chapel.
At 320 m level, tourists walk through a network of historical workings: shafts, drifts, inclines and chambers where a collection of mining machinery is exposed. These are authentic devices used for coal extraction throughout the 19 th and the 20 th centuries. The drifts are partly lined with steel arcs and anchors. Total length of this trail is about 2.5 km. Visitors can recognize the mining methods used in the 19 th century. They can also watch the operation of the conveyor belt protected by mixed roof support: steel props and timber posts with caps and the face shearer as well as some outcrops of coal seams of the Paralic Series (Wilanowski et al., 2009(Wilanowski et al., , 2015Tab. 1;Figs. 2A and 4F). Since 2011, an additional adventure available for the visitors has been the only electric underground suspension rail in Poland (Fig. 4G) and a unique pub located in an old chamber (Fig. 4H). Quite a high number of concerts and theatrical performances are held there (www3). The Coal Mining Museum in Zabrze has also the exhibition of coal specimens from the USCB area (www3).
The interest in the two geotourism attractions in Zabrze was always very high. In the years 1995-2012, the total number of visitors varied from 45,107 up to 63,051, with an exception of 2005, when it decreased to 37,136. However, in 2013, it dropped down to 5,591 (www8; Tab. 2). The underground trail of the "Królowa Luiza" Mine was closed in the years 2011-2017, because of restoration works. In 2014, the surface facilities of the mine have been opened for tourists. This explains a noticeable increase of attendants to the Zabrze "mining heritage sites". Since 2014, the number of visitors to these two geotourist attractions in Zabrze has rised from 121,483 up to 182,374. Since the two new underground trails of the "Królowa Luiza" Adit have been developed for tourism: the "Familiar Route" (since 2016) and the "Water Route" (since 2018), the total number of visitors to all three sites in Zabrze have increased up to the top value of 223,820 in 2019 (www8; Tab. 2).
In 2020, the "Królowa Luiza" Adit and the "Guido" Mine were recognized by the President of the Republic of Poland as a monument of history under the name of the "Zabrze -a Complex of Historic Coal Mines". Thus, these were included into the most valuable historical buildings in Poland. Owing to its international importance, Zabrze town now plays the role of the European centre of industrial heritage, related to the "black gold" historical mining (Gola, 2020).
In 1889, the Mining School has been established in Dąbrowa Górnicza, as a secondary technical school dedicated to education and practical training of foremen for mines, smelters and ironworks. In 1919, the school evolved into the State Mining and Metallurgical School, known under the nickname of "Sztygarka" ("sztygar" in Polish means "foreman" and "sztygarka" is a slang name of chamber, in which foremen work). Practical training required underground workings, hence, since 1927, a system of galleries has been cut at 10-15 m depth below surface (Wójcik & Chmura, 2008;Cygnarowska, 2017).
The practical training at the "Sztygarka" Mine has ceased in 1994. The "Paris" Mine was closed in 1995 due to reserves' exhaustion. In the following years, the local authorities debated the adaptation of existing mine workings for a mining museum, as it was the only existing remnant documenting the long history of mining activity in Dąbrowa Górnicza. Hence, the "Sztygarka" Training Mine was adapted for tourism in 2010 (Chmura & Wójcik, 2009;Glimos-Nadgórska, 2017;www2).
The "Sztygarka" Training Mine has become a branch of the "Sztygarka" City Museum (Sobota, 2007;Cygnarowska, 2017;www2), founded in 1997 and situated in its close neighbourhood (Fig. 5). Tourists can walk along selected old workings of total length about 650 m, cut at two mining levels vertically spaced by about 14 m and interconnected with the northern incline No. I (Duży & Preidl, 2011;Figs. 5, 6). The deepest No. III level, (Figs. 5, 6A), is currently inaccessible for visitors. At the upper, No. I level, in the southern drift (Figs. 5, 6A), visitors can see the brick lining (Fig. 7A) and a collection of various types of mine carts used for coal haulage (Fig. 7B). In the western drift (Figs. 5, 6A), ventilator and fully equipped electric switchboard are exhibited. When walking along the northern incline (Figs. 5, 6B), the tourists recognize the ventilation pipe delivering fresh air to the workings (Fig. 7C).
At the lower, No II level, in the overwall drift (Fig. 5), tourists can see the outcrop of a coal seam belonging to the Rudy Beds (Wilanowski, 2016;Tab. 1 ; Fig. 7E). The overwall drift has a steel arc lining (Fig. 7D). The No. II longwall, started at the beginning of the southern incline (Fig. 5), is equipped with a shearer (Fig. 7F) and a conveyor belt (Fig. 7G) whereas its roof is protected by steel arches and hydraulic props (Fig. 7G).
In the "Sztygarka" City Museum, visitors can also examine the collection of coal specimens taken from various outcrops within the Upper Silesian Coal Basin area (Fig. 7H).
Despite the fact that the underground trail at the "Sztygarka" Training Mine is much shorter than the other such objects in Zabrze, the interest in this facility and the City Museum was always very high. They have become a geotourism attraction widely known in Poland and in the world. In the years 1998-2009, total number of visitors to the "Sztygarka" City Museum varied from 1,150 to 5,654 (www8; Tab. 2). When the underground trail has been opened for public in 2010, a noticeable increase was observed of total number of tourists visiting these two facilities: from 12,317 up to 19,294. However, in 2019, the number decreased to 10,717 (www8; Tab. 2). When the tourist trail at the "Sztygarka" Training Mine is extended by opening the drifts at No. III level (Polko, 2018;Figs. 5, 6A), the significant increase of tourist flow is expected.

Historical lead-zinc-silver ore mining in Tarnowskie Góry town
The ore mining in Tarnowskie Góry town dates back to around 1490. These mineral resources were the basis for metallurgical industry in Poland and in Central Europe (Pawlak & Filak, 2017). Large number of surface excavations, shafts and galleries were cut in Triassic dolomites, in order to reach silver, lead and (later) zinc orebodies. Total length of these old-workings is about 150 km. At the beginning, only primitive, manual methods were used with hammer as the most popular rock-cutting tool. The output was transported to the shaft stations and hoisted in kibbles. The galleries had to be drained when operations were run beneath the groundwater table. Hence, kibbles were used for draining the mine, but inflows were too high due to karstification of dolomites. Thus, special drainage adits had to be cut. In addition, horse-driven windlasses were used for mine drainage, as well. In the 17 th century, ore exploitation ceased due to the Thirty Years' War and later Prussian-Austrian war in the Silesia. In 1784, a new "Fryderyk" ("Frederick") mine was constructed in Tarnowskie Góry. Its workings were drained by water adits (Moszny, 2003). The last adit, named the "Głęboka-Fryderyk" ("Deep-Frederick", recently the "Czarny Pstrąg" Adit) was cut between 1821 and 1835. Its small part, about 600-m-long, has been adapted for tourism (Piernikarczyk, 1984;Dzięgiel, 2008;www4).
Geotourism vol. 17, 1-2 (60-61) 2020 https://journals.agh.edu.pl/geotour The patients of the Upper Silesian Rehabilitation Center (in operation since 1961), situated near the adit were especially numerous among the visitors to the "Czarny Pstrąg" Adit. When the Historical Silver Mine was also opened for tourism in 1976, the total visitor number of both sites has increased noticeably, from 79,081 in 1977 to 88,887 in 198388,887 in . In 1984

Conclusions
Statistical data analysis of tourist flow in the underground trails of the central part of the Silesian Upland indicates that their geotourism attractiveness and popularity are very high. Currently, number of tourist visits to the Historical Silver Mine and the "Czarny Pstrąg" Adit in Tarnowskie Góry, and to the historical coal mines in Zabrze: the "Królowa Luiza" Adit and the "Guido" Mine are higher than those to the popular Coal Mine in Nowa Ruda town and, for a few years, have been almost equal to the attendance to the Gold Mine in Złoty Stok town (Tabs. 2, 3) (Kruczek & Szromek, 2011;Ziarkowska, 2019;www8;www9). This perfectly documents the increasing dynamics of the tourist flow in the historical mines.
The geotourism attractions in Tarnowskie Góry were the first post-industrial underground mining heritage monuments in the Upper Silesia adapted for tourism in 1957 and 1976. Hence, since the 1980s, they have been visited more frequently than the historical coal mines in Zabrze and in Dąbrowa Górnicza (Tabs. 2, 3). As these sites have already been included into the UNESCO World Heritage List, the Tarnowskie Góry Land Lovers Association (www4) in cooperation with the local authority attempted to design the future Upper Silesian Metal Ore Mining Geopark. Owing to that, these facilities could become even more widely recognised all over the world.
The tourist visits at the "Królowa Luiza" Adit and the "Guido" Mine in Zabrze have increased noticeably only in the recent years (Tab. 1). Therefore, the local authorities, in cooperation with numerous foreign organizations associated with the industrial heritage protection and some other European international institutions, should make an effort to include also these objects into the UNESCO World Heritage List. This may help to make these sites more recognizable and to achieve an additional great success, despite the fact that Zabrze already plays a significant role as the European centre of industrial heritage related to the "black gold" mining. Hence, the local authorities may also attempt to develop the Upper Silesian Coal Mining Geopark. At the beginning, it could include only the two historical coal mines in Zabrze, but in the future, it may be extended to some other sites in the USCB area, when the recently operating mines cease their activity and their relics become accessible for visitors.
As a result of the creation of the Upper Silesian Metal Ore Mining and Coal Mining geoparks, some exchange of experiences and information concerning the restoration and modernization of the sites among local authorities can be much easier. This could lead to the increase of their global rank and reputation.
The "Sztygarka" Training Mine in Dąbrowa Górnicza is still much less known as a geotourism attraction than the other objects described above. First of all, this underground trail is much shorter than the others, except for the "Czarny Pstrąg" Adit. It has been the latest object, opened to the public in 2010 except for the two new trails developed later at the "Królowa Luiza" Adit. Hence, it could not be effectively promoted and, thus, so widely known, as yet. However, after extension of the trails at No. III mining level (Figs. 5, 6A) and after general restoration, the "Sztygarka" Training Mine will gain a potential to be much more popular in Poland and in the world, particularly if included into the future Upper Silesian Coal Mining Geopark. The perspectives of tourism development in the central part of the Silesian Upland, based upon their industrial heritage and geoheritage attractions of the central part of the Upper Silesian Coal Basin seem to be very optimistic.