A novel collection of medical curiosities housed in an 18th-century surgeon training academy.

Museum on earth sciences featuring a recreation of a famous curiosity cabinet.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

The gilded, masterful astronomical clock will calculate time, dates, and planetary positions for thousands of years to come.

Hans Christian Andersen for the postmodern world.

This sublime architectural marvel is a rare example of an expressionist church.

On this wooded path, a stained-glass window creates a spellbinding forest cathedral.

A huge museum of much more than just agriculture displayed in a princess's palace.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

A series of labyrinths in the Nevada desert inspire meditation and calmness.

A strange aquarium with stuffed fish, and almost no water for them to swim in.

The massive cave church of Cairo's Zabbaleen community is one of the largest Christian churches in the Middle East.

The patron of this extravagant Art Nouveau confection insisted that nothing less than a boat should project from its facade.

An ancient instrument used to measure the waters of the Nile so Egyptian farmers would know whether to expect famine or flood.

Dine amidst exotic plants at this former royal greenhouse.

This cubist Vienna church building looks like some sort of alien stonehenge.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

The final resting place for the remains of 143 Habsburg royalty.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

Collapsing castle on the Hudson river was once the storage site of military surplus business.

The right to a full beard is honored by the grave of a man who was attacked and jailed due to his facial hair.

This old mill and former police station now present a world-class collection of Orthodox iconography.

This railroad tunnel was once the longest in Massachusetts.

This dam in the woods, built by Henry Ford with only manpower and oxen, holds no water and serves no purpose.