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

This historic Amsterdam bar used to accept sailor's monkeys as payment.

Amsterdam's former hotspot for public executions and dissections.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

This unattributed sculpture in Amsterdam is hiding in plain sight.

This macabre monument atop an ancient well gives a nod to a brutal episode in Scottish clan history.

Built to hold the worst of the worst of the Nazi war prisoners.

This unusual rock looks like a giant, otherworldly mushroom sprouting atop a cave.

This tiny island is home to the world's largest colony of Northern gannets.

A cross marks the spot in a small Scottish village that claims to be the exact center of the country.

Macbeth's infamous "Great Birnam Wood."

A church that bred legends, and served as an inspiration for the Da Vinci Code.

This natural crater along the coast of Jersey may take its name from the devil statues who have watched over it.

This famous archeological mystery may be an ancient example of movable type.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

The fishing boats that moor in this small lagoon enter and leave through a tunnel to the sea.

Two geological phenomena in one precarious locale: a towering stone window, and a deep blue void.

Copenhagen's celebrated theme park and gardens.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

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

Hindu temple of the dead home to hundreds of long-tailed macaques.

A building so large that it has its own weather.

The National Railway Museum in York is the largest railway museum in the world, attracting almost 1 million visitors per year.

Follow the original medieval paths that wind through this intriguing section of the city.