The Wieliczka Salt Mine looks pretty amazing.
.WONDERS OF AN UNDERGROUND WORLD
By BERLIN CORRESPONDENT
TECHNICAL WORLD MAGAZINE
WELL known to European tourists but passed by most globe trotters —who in their hurried journey across seas and continents, have no time to bestow on anything outside of the beaten tracks—are the salt mines of Wieliczka, Galicia, whose origin is lost in the darkness of the times, while their history is traced to about 1000 A. D. After being temporarily abandoned as a consequence of Tartar incursions and the resulting depopulation and impoverishment of the country, they were restored during the reign of Boleslas by immigrating Hungarian miners.