A neo-Gothic mansion now houses a wunderkammer of analog tech that hits on all the senses.

Apartment complexes built into huge repurposed natural gas tanks.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

Legends surround an ancient tree trunk riddled with nails for good luck.

Baroque celebration of the end of the Great Plague of Vienna.

Handsomely crafted representations of our round planet.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

Submerged lava formations create incredible waterworks.

Martin Bricelj Baraga's monolithic sculpture measures the blueness of the sky, and changes color to match it.

A whimsical bridge adorned with decorative dragons.

A tiny church on a man-made island in the Adriatic.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

The big toe of this towering monument to a Croatian national hero is worn from years of superstitious rubbing.

Now harmless, this looming post struck fear into the heart of medieval troublemakers.

An ancient knight and a symbol of the city's freedom.

This scale model of our solar system hid in plain sight for years before a physics team sought out all the planets.

Gargoyle head that brings good luck.

Where the lovelorn find a home for their sentimental keepsakes.

A musical instrument played by the sea.

Numerous impressive carvings are embedded in the trees lining this street in Marrakech.

The oldest known university in the world is in Fez, Morocco.

Traditional 11th-century outdoor tannery.

An awe-inspiring mosque in Morocco with one of the tallest minarets in the world.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.