Once a safe haven for locals engaged in blood feuds, this 400-year-old fortified tower is now a museum showing what life was like for those lying in wait within its walls.

The encased skull that is widely believed to belong to St. John the Baptist.

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

This 1920s Dutch barge is now a floating bookstore.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.

This hospital helped pave the way for treatment that drove down child-mortality rates in 19th and 20th centuries.

You will not be able to miss this building.

This former medical factory gives home to cutting edge arts in the shadow of a gas works.

A local museum honors the overlooked discoveries of Mary Anning, one of the first professional fossil hunters.

This marine reptile was discovered by one of the 19th century's greatest fossil hunters.

Down a pint of ale where the Bishop of Ely's servants slept in 1546.

A rocky outcrop where monks hid their most holy relic while escaping Danish invaders.

The largest preserved walking dragline excavator in Western Europe.

The oldest operating roller coaster of its kind, the Montaña Suiza has been thrilling riders since 1928.

A medieval village holds a very modern hotel.

Hundreds of preserved dinosaur footprints can be found along a hiking trail in this small village.

For more than half a millennia, this automaton has rung an hourly bell.

The most elaborate of 12 medieval arched doorways to the old city of Burgos.

This Gothic church houses ornate royal tombs and a magnificent gilded altarpiece.

A charming Spanish village sits atop this natural limestone overpass.

The former home of a conniving 17th century politician is now a high-end hotel.