It is the oldest salt mine in Poland (rock salt having been discovered at Bochnia several years earlier than at Wieliczka), and remained in continuous use from the mid-13th to the 20th century. Bochnia itself is one of the oldest cities in Lesser Poland (Małopolska), and provides an example of a medieval mining town. To this day, the head frames of the Campi, Sutoris and Trinitatis Shafts, along with the mine’s other above-ground structures, define Bochnia’s landscape. The Sutoris Shaft, dating from the mid-13th century, is the oldest operational salt mine shaft in Poland, and now serves to take tourists and health resort visitors down into the mine. From the latter half of the 16th century up to the early 1990s, the Campi Shaft (excavated in 1556-1568) was the main extraction shaft of the Bochnia Salt Mine.

The mine’s pits lie at various depths, from 70 m to 289 m, incorporating a total of c. 60 km of passages and galleries. In particular, the wholly authentic interiors of Bochnia’s mine offer an opportunity to learn about the extraction techniques formerly used in Polish and European mining. Pits dating from the 13th-18th century survive in excellent condition thanks to measures undertaken since the mid-18th century to protect the mine with a system of roof supports, timber cribs and salt pillars. Some of the most interesting and unique features of the mine are its horizontal headings, known as drifts, and its vertical pits. Reconstructions of transportation devices help visitors gain an understanding of former mining techniques, and a copy of a map (based on a 19th-century original) detailing all of Bochnia’s pits illustrates how the mine evolved and expanded. On Sienkiewicz level there is a large treadwheel which was used for raising brine, whilst a four-horse treadwheel used for removing water from the mine is on display in the Rabsztyn Chamber (mined since the 18th century). The treadwheel chamber next to the Ważyn Shaft features a huge horizontal treadwheel which retains some of its original structural parts. The Mysiur Chamber is notable for the authenticity of its historic interior, unaltered in over two centuries. From the 1760s up until 1963 it housed stables for the horses working at the mine. Extant timber cribbing and platforms on which the miners stood when working the salt face can be seen here. The 16th-century complex known as the Christian Chamber is striking both in terms of its historic and visual merits. The unusual shape of its narrow, tapering interiors was dictated by the almost vertical seam of salt located there, and led to it being referred to as an underground cathedral.

The Ważyn Chamber is particularly noteworthy (its exceptionally rich salt deposits having been mined from 1697 until the 1950s). It lies at a depth of c. 250 m, measuring 255 m in length, with a maximum width of almost 15 m, and a height of over 7 m. Its vast, splendid interior has no supports. The ceiling and side walls are a fantastic sight, being interspersed with layers of salt and anhydrites forming natural embellishments. The chamber has a distinctive microclimate attributable to a stable temperature (14-16^oC), high humidity and clean, ionised air saturated with sodium chloride and microelements. Since 1993 the chamber has been used as a health resort (for inhalation therapy and recreation purposes).

A peerless historic feature of the Bochnia mine is the largest and best preserved of its once numerous chapels - St Kinga’s Chapel. Its origins date back to 1747, and it bears witness both to the profound piety of the miners and to their artistic skills, as demonstrated by component parts of the chapel fittings. The chapel’s irregular ground-plan is delimited within a rectangular space of 21 × 31 m, and its average height amounts to 5-6 m. One of the chapel’s highlights is the main altar dedicated to St Kinga, adorned with a 19th-century painting by T. Krasiński depicting the legend of Kinga’s miraculous ring, to which the discovery of salt in Bochnia is attributed.