Yugoslavia's biggest underground airport lies in ruins.

One of the largest caves in the world open to the public.

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

A museum in the childhood house of a medical pioneer.

Bohemian paradise covered in majestic forests.

A church of bones, decorated with 40,000 human skeletons.

A museum of alchemy and a basement laboratory all housed in an ancient building in a Gothic tower.

Two monstrous faces loom over a village in Czechia.

Two stunning 17th-century libraries and a cabinet of curiosities.

A crucified and bearded female saint.

A saintly relic hidden in a Prague church basement.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

A collection of anatomical samples from one of the first anthropologists to suggest that humans reached North America by crossing the Bering Strait.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

Macabre astrological automaton clock dating to the late 1400s.

Underneath this small church are 15,000 bones, arranged by an obsessive academic.

This small museum collects the Christian remembrances which would otherwise be forgotten.

A former plague hospital turned medical museum.

Unsurprisingly, Holland is home to one of the most magnificent flower gardens in the world.

Oldest Museum of the Netherlands is a true cabinet of curiosities.

The history and future of cannabis.

The world's only museum devoted to the wonders of fluorescence.

Museum preserving torture methods from the past.