One in a pair of subterranean caves created by an ancient eruption of Mount Fuji.

Bangkok celebrated its shifting monarchy with a militaristic homage to democracy.

You can walk up Thailand’s naturally non-slip waterfall.

Each time a baby is born in Ghent, these streetlights flash in silent celebration.

Controversially claiming the title of world's biggest bass drum, UT's Big Bertha was once made radioactive by the Manhattan Project.

This simple frog painting created by musician Daniel Johnston embodies the spirit of Austin.

The man who wasn't there.

A collection of massive stacked rocks in Texas includes a snarky note on the benefits of modern technology.

Tracks near this Texas nature site were once thought to support the Creationist belief that man and dino coexisted.

Pulled from the rubble of one of the worst modern tragedies, a steel crossbeam became a symbol of hope for New Yorkers.

The 28-foot granite map plots the locations of 40 theaters in New York City.

A notorious punk house turned co-op.

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

Two gravestones clasp hands over the religious divide.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

This cheese shop also houses a museum devoted to Dutch dairy.

This fairy tale forest hides scenes from some of the more obscure and bizarre Western nursery stories.

Birthplace of the "Cat in the Cradle" and a cluster of iconic, original windmills that let the Dutch tame the seas.

A public urinal so pretty, it was declared a national monument.