Roman ruins top white travertine terraces formed by ancient hot springs.

An oasis of shade and color amidst the bustle of the old city.

This cascade of mineral-rich hot springs and waterfalls is an oasis in the Jordanian desert.

Romania's only crater lake with water as pure as if distilled.

The romantic botanic tunnel feels like a well-kept secret.

Some call this eerie forest of crooked trees the "Bermuda Triangle of Romania."

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

This fairy-tale castle would make Dracula (who is said to have been imprisoned there) jealous.

This massive underground salt mine now holds a sci-fi theme park in its depths.

Moss and stone turn this waterfall into an otherworldly liquid veil.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

In Hong Kong, a fairytale flower tunnel is hidden within the gardens of a public housing complex.

Legend has it a sacred treasure hidden by an ancient guru was revealed with a burning butter lamp from these waters.

The small cliffside monastery known as the Tiger's Nest is said to be the meditation site of an 8th-century Buddhist master.

Spirits from these lakes are said to produce the local weather and odd phenomena as they bicker between themselves.

In this African village, the walls of the chief's compound are painted with beautiful traditional designs.

Abandoned castle was once a grand example of Russian privilege, built exclusively to win a frivolous bet between noblemen.

It's hard to believe the dizzying patterns covering this abandoned mine are completely natural.

Dr. Strangelove-esque tours reveal the inside a bunker once reserved for Stalin himself.

Built to ward off Napoleon's army, this city-sized abandoned Russian fort is now perfect for urban exploration.

The widest waterfall in Europe is a natural wonder and one of the only places where fish are caught in the air.

Medical museum that houses most notably the taxidermied remains of Vladimir Demikhov's famous two-headed dog experiment.

This Luxembourg cave is covered in cryptic looking marks left by mining activity.

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