The 22,000-square-meter Chapel of St. Kinga was created by miners with everything, including the chandeliers, made from rock salt.
According to one source (Northern Illinois University): "St. Kinga's Chapel is the largest among underground chapels in the Wieliczka Salt mine. It is also the most impressive and opulent underground temple. It was laid out in 1896, in the space created after the excavation of a huge green salt block. It is over 54 metres long, 15-18 meters wide and 10-12 meters high. St. Kinga's Chapel is actually a sizable subterranean church carved in rock salt and embellished with salty sculptures and bas-reliefs (even the chandeliers are made of salt crystals...). ... St. Kinga's Chapel, at the depth of 101 meters, is a masterpiece created by the miner sculptors: the brothers Józef and Tomasz Markowski, and Antoni Wyrodek. The high altar with the statue of St. Kinga is the work of Józef Markowski and his assistants. ... St. Kinga's Chapel, which is a unique gallery of rock-salt art and a concert hall, apart from providing visitors with [an] aesthetic experience, is a living centre of religious observances. Solemn Mass is said here on special occasions, and on 24th July (feast of St. Kinga) 4th December (feast of St. Barbara) and 24th December (Midnight Mass), as well as on each Sunday morning."