After 400 years of being closed to the public, this monastery's underground tunnels and secret garden are now a museum.

Dynastic Home of the De Piro Family.

This church is named for one of the most dramatic tales in the early Christian church.

These temples are among the oldest free-standing stone buildings in the world.

This prison on the Maltese island of Gozo is almost 500 years old, and they have the graffiti to prove it.

The site of an early Arthurian battle and the dwelling-place of prehistoric people and (possibly) an ancient race of giants.

Makers and sellers of the original and finest York Ghosts.

You'd never know the houses at 23-24 Leinster Gardens were fakes—until you see the train tracks on the other side.

The longest stone bridge in England has an impressive history that dates back over 700 years.

World's second largest particle accelerator, where nature reveals its secrets.

Dedicated to the works of the legendary special effects artist.

A significant example of Czech cubist architecture—a style you won't find anywhere else in the world.

Steadily reminding Czechia of its past.

The slender brass strip in Prague's Old Town Square was used to tell time from 1652 to 1918.

This spooky statue sits outside a famous Prague theater.

The palace window through which Protestant nobles flung two Catholic regents, thus sparking the Thirty Years' War.

Looming communist pillar with a Czech twist.

A series of playful yellow penguins share a serious message about the environment.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

What looks like a suicide in progress is actually a statue of Sigmund Freud.

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

Countless grotesque faces stare out from this eerie Prague art wall.

The hidden lair of an alchemist rediscovered in a 2002 flood.

Macabre astrological automaton clock dating to the late 1400s.