The ruins of a medieval seminary some say is the oldest university site in Scotland.

This remote British Imperial telegraph relay outpost drove men insane.

Elaborate patterns adorn the city's disappearing traditional architecture.

The Brutalist building harbors an unusual inverted dome that swoops down over its central sacred room.

The oldest surviving mosque in the UAE has mysterious origins and unusual architecture.

A replica viking ship from the Chicago World's Fair is still in dry dock in an Illinois park.

The beautiful, ornate weather station is the most popular geocache in Salzburg.

The antique hotel still has a jail in the basement, though the cockfighting ring is long gone.

The 14th-century ruins are said to contain healing powers.

An extravagant monument to an extravagantly unpopular Emperor.

World's largest cave was only discovered in 1991, and now offers tours to the public.

This oddly placed 15th-century church is one of only six bridge chapels left in England.

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

“It has nae lugs!”

The world's first and only three-segment bascule bridge folds up into the shape of a capital "N" to let boat traffic through.

It's good luck to be mocked by this monkey.

A whimsical brother of the nearby Fallen Angel statue takes the falling part quite literally.

This bridge is embedded with a giant steel dragon that breathes fire from its mouth.

Vietnam's feral abandoned water park offers access to a post-apocalyptic funscape, now with fewer crocodiles.

Giant pagoda houses the car that drove Thích Quảng Đức to his death by self-immolation.

This network of tunnels housed an entire village for years, and even had a hall for screening movies.

A tower marking the spot where Yugoslavia began its resistance against the invading Nazis stands neglected, but not quite forgotten.

A diminutive plaque recalls the treetop sniper who almost killed Abe Lincoln.

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