19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

The Great Fire of London and the regulation of one-way streets both started in this alley.

Its collection includes a broad array of social, geographic, graphic design, and political history.

This former quarry is now a vibrant labyrinth of magical in situ sculptures.

The mummified heart of a saint lives on in this church—after a brief hiatus when it was stolen.

Experience what life was like in Ireland during the Viking and medieval ages.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

Medicinal spa created with the discharge from a geothermal energy plant.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Stockholm's narrowest alley is barely over two feet wide.

Small Easter eggs are hidden in the ventilation holes of the city's newest trains.

It houses the remains of a 17th-century version of the Titanic.

Sweden's "good old days" painstakingly re-created in a model village.

Russia's own leaning tower was built on a tragic historical fable.

Replica of mosque destroyed by Russia in the 16th century.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

Former headquarters of the KGB.

One of the world's tallest statues is also one of its most hated.

World's largest bell sits on the grounds of the Kremlin in Moscow.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

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