A Cold War secret surveillance tower used to spy on radio communications.

These 17th-century mummies are no longer naturally preserved, but remain on display today.

Tel Aviv's popular neighborhood went though endless waves of transformation.

The maze-like transportation hub contains abandoned areas, derelict stores, and a resident bat colony.

Europe's largest natural bridge has a 19th century royal chateau built into its side.

Bohemian paradise covered in majestic forests.

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

This Czech military museum is home to pink tank that was once a symbol of art and political rebellion.

This former quarry is now a picturesque gorge that hides a sunken lake.

The tunnel's elegant proportions keep you snug with no claustrophobia freak-out.

Steadily reminding Czechia of its past.

Increasingly decayed figures stand as a powerful reminder of the human costs of Czech Communism.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

This automated sculpture of two men peeing will spell out text messages with their micturition.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

A surreal statue honoring Prague's favorite literary son.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

A controversial artwork draws attention to the dark history of Prague's "Suicide Bridge."

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

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

This renaissance château was home to an infamous witch hunter who sent a hundred suspected witches to their deaths.

An enormous and lavish Gothic church in Czechia.

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