The first exposition is in the cellars of the 14th-century town hall, which once stood on the Olkusz Market Square. The cellars discovered by archaeologists have been adapted for sightseeing. Walking a few metres under the Market Square, one can see the exhibition that presents the history of Olkusz, called the Silver City due to the tradition of silver and lead mining dating back to the Middle Ages. Numerous touch-sensitive multimedia presentations give a chance to learn about the history of the town and its inhabitants, and to see old documents, engravings and maps. In the vaults we can also see a replica of an astrolabe, namely an astronomical device which once belonged to the famous Olkusz astronomer and astrologer Marcin Bylica. In the former city dungeon we can watch an animated scene depicting the everyday life of the medieval city and see instruments of torture. The second underground exhibition is located in the cellars of the former Royal Quarter, where the headquarters of Olkusz mining authorities used to be. It is devoted to Olkusz mining and metallurgic traditions, and a mint operating at the turn of the 17th century. A spatial model showing old Olkusz mines is a great attraction. There is also a part devoted to metallurgy, where replicas of furnaces used for smelting lead and silver can be seen. One of the basement chambers, called the "Silver Chamber", is a story about the history of silver from antiquity to modern times. There you can see a replica of the Silver Cross of Olkusz Guards, the original of which is in the Olkusz Basilica. During the revitalisation of the Old Town, almost 100,000 antique objects were obtained, including coins, ceramics, pieces of lead, leather, elements of clothing, copper weights and ornaments. More than two hundred of the most exciting exhibits were selected, including 130 coins, which underwent conservation, and some of them can be seen in underground exhibitions. The curiosities presented at the exhibition include a mould for casting discs from which coins were minted, the so-called counterman produced in Nuremberg probably in the 15th century and used in the Olkusz mint, as well as a lead seal for textile articles from the turn of the 17th century, which came to Olkusz from London.