In the days before house numbers, these colorful signs held clues about various buildings' purposes.

A unique work of automotive art calls this shopping center home.

This beautifully designed star-shaped fort was the premier defense system of the late 1500s.

The nerve center of a massive, state-of-the art radio telescope that sprawls across Western Europe.

A decomissioned facility where the German "Transrapid" maglev trains were once tested.

A statue commemorating 'the greatest inhabitant of Amsterdam of all time.'

Europe's first floating restaurant is home to a hilarious legend.

Pull up and have a drink at a museum filled with hundreds of years' worth of shipwreck artifacts.

This no man's land slicing through the island is strewn with abandoned relics of another time.

Carvings in Turkey's Marble Road may have directed ancient Romans to a hidden brothel.

The ancient latrines of the Greeks, in all their public glory.

The real-life ‘Severance’ office building.

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

These small, triangular, colorful houses are a staple of Madeira Island.

An Amsterdam School landmark combining a museum and social housing.

One of Amsterdam’s most popular cultural and recreational complexes is on the site of a former gas works.

A unique World War II memorial commemorates where the American B-17 bomber Man-O-War crashed.

This neighborhood of futuristic ball houses looks like an alien settlement in a science fiction film.

Abandoned since 1998, this train station has become an oasis for urban explorers.

The highest point in Belgium is a staircase to nowhere.

In the heart of Luxembourg's "little Switzerland" weaves a breathtaking natural sandstone canyon with a mythological past.

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

This modest monument marks the only point of intersection between longitude and latitude in the Grand Duchy of Luxembourg.

Germany has its very own Centralia, whose spark remains attributed to "spontaneous combustion."