The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

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

This artificial cave looks like something out of a fairytale.

This folk art compound was built by a fortune teller on the advice of three people from the future.

A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

One of the world's most complex timepieces.

A Museum of Psychiatry in a still-operating mental institution.

This collection of solar timekeepers includes the world's first digital sundial.

A 14th-century fortified keep showcases the masterpieces of an ingenious 20th-century clockmaker.

A huge wooden clock that is so beautiful its creator was forcibly blinded.

There has been an astronomical clock on this spot since the 14th century.

Home to the "Circus" trees created by Axel Erlandson.

Centuries-old bridges grown from tangled roots.

This Sumatran root bridge took almost 30 years to knit itself together.

Natural cathedral designed by Italian artist Giuliano Mauri.

Living trees form the structure of an open-air palace.

Macabre astrological automaton clock dating to the late 1400s.

Home to 200 plaster casts of Scandinavian proboscises.

This picturesque Umbrian city has a subterranean side that has long remained hidden.

A town church once nearly submerged by the damming of a river is now hauntingly visible as the water recedes.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

This vast, water-filled underground labyrinth can only be toured by boat.

An abandoned Nazi explosives plant founded by the inventor of dynamite is now an underground museum.

A winding, blood-red tunnel of hardened lava navigable by foot.