This bone-filled cave got its name after they found 140 bear skeletons inside.

No one knows who built this strange cave of worship or exactly why.

The temple that withstood the Nazis.

Outstanding, eerie frescoes and decorations fill this 19th-century monastery.

The unusual sculptures are believed to be powerful political symbols.

Abstract monuments express sorrow and resilience at the site of a horrific massacre in Nazi-occupied Serbia.

Structure built from the skulls of vanquished foes.

This 14th century castle withstood years of battle but is now sliding off the hills into the Danube.

Bronzes and busts that once stood in the city's main squares are now relegated to a small hidden courtyard.

What happens when you cross a mayor and a painter?

A naturally beautiful, seemingly bottomless deep blue spring.

A relic from the Industrial Revolution got a second life as a contemporary performing arts space.

The Slovenian architect designed many landmarks in the capital city, including his own dream house.

This one-time health resort was used by aristocrats around the world.

This massive subterranean fissure is known as the "underground Grand Canyon."

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

A little sculpture with a large wardrobe.