Overlooking a Scottish loch, this beautifully crumbling castle once inspired a poem by William Wordsworth.

This eclectic sanctuary is a hodgepodge of various architectural styles, all crammed into one building.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

Inside a Scottish castle hangs the tattered remains of a flag with murky origins and supposed magic powers.

Islanders once used this dramatic, otherworldly landscape to hide their cattle from Viking raiders.

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

The last manually operated turntable ferry in the world.

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

In 1990, this 37-foot red steel bottle sailed from New York to England.

The longest staircase lock in Britain.

One of the world's heaviest musical instruments towers within a popular urban park.

Tiny memorials honor individual victims of the Holocaust.

This water-tower-turned-high-end-apartment building was once the site of an early Nazi concentration camp.

Beneath the impressive baroque cathedral that rises from the center of Berlin lies the largest collection of Prussian royals in the world.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

Built for the 1962 World Cup, this fully functioning botanical clock is still ticking.

The Chilean mountain is freckled with (relatively) small European telescopes.

A surprisingly detailed model of the world's most powerful radio telescope.

A charmingly unusual prefabricated metal church designed by Alexandre Gustave Eiffel.

One of the world's most advanced radio observatories sprawls across the Atacama Desert.

The ruins of a pre-Columbian fortress city so secure it held off the Spanish conquistadors for over 20 years.

The world's most remote airport.