"During a tour of the more-than-700-year-old Wieliczka Salt Mine, you’ll travel through a labyrinth of underground corridors and stairs leading to a variety of fantastically shaped chambers, chapels, salt sculptures, and subterranean lakes. Exploring with a guide is essential, as the mine is home to nine separate levels and more than 2,000 excavated chambers. The Tourist Route, which starts at the Daniłowicz Shaft, takes about three hours to complete but covers only a small stretch of this fascinating underworld. For a more adventurous experience, choose the Miners’ Route expedition, which begins at the Regis Shaft (about a 10-minute walk from the main Daniłowicz Shaft) and allows guests to try their hand at working underground. The salt mine is very popular, so buy tickets far in advance, either online or from a trusted tour operator. And wear comfortable shoes—a visit here involves a lot of walking."