The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

An underground city of salt.

Naturally formed rock city in Poland.

Relive a Polish uprising via an enormous, century-old cyclorama.

A wunderkammer of gold and silver reliquaries and ancient saintly bones.

An ancient knight and a symbol of the city's freedom.

A castle perched precariously over the Crimean Sea.

The remains of a sunken military ship wreck visible through clear water.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.