This Polish cave has housed a dragon, a brothel, and an enduring legend.

An alien church provides much needed silence in the midst of a Finland shopping center.

The oldest museum in Russia is home to a fascinating collection of nearly two million anthropological artifacts and anatomical curiosities.

The Guardian of Tallinn.

The oldest church in the Estonian capital is home to over 100 fantastical cemetery coats-of-arms.

An empty relic of the Moscow Olympics crumbles away in Estonia's capital.

A former imperial sea-fortress and Soviet prison.

A subterranean house of worship carved right out of the bedrock.

An abstract monument to a symphonic composer.

Villas that once served as playgrounds for the rich now fall away in decay.

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

Monasteries on rock pillars, once accessible only by frayed ropes.

This ominous Albanian fortress houses tanks and downed planes as a reminder of their victories over Western imperialism.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

This exclusive resort has completely covered a tiny Balkan island in a 5-star warren of guest rooms.

A majestic lion statue guards this Parisian botanical garden, and feeds on an unsettling item.

Natural history museum celebrating biodiversity with a parade of taxidermy animals.

Site of a classic 19th-century physics experiment to prove the earth is rotating.

Croatia's towering concrete blossom grows from the site of a World War II concentration camp.

Balconies that have a most unusual accent.

A French library that makes sure its love of books is writ large... giant in fact.

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

When the imprisoned pope's remains were finally returned to the Vatican, his heart stayed behind in France.

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.