Latvia's symbolic mountain-shaped national library is home to millions of cultural tomes.

3,000 market stands in five former Zeppelin hangars.

A black cat protests the City Guild in Riga's Old Town.

This celebration of Latvia’s freedom and independence avoided demolition over half a century of Soviet occupation.

A former Latvian headquarters of the brutal KGB secret police is now open as a grim reminder of their atrocities.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

This surreal statue brings a famous French novel about a supernatural cad to arresting life.

Paris' linguistic guide to the international language of, yes, love.

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

Go inside to really appreciate this 500-year-old technological masterpiece.

This subterranean necropolis holds three floors of antler-dug grave caves.

This prison on the Maltese island of Gozo is almost 500 years old, and they have the graffiti to prove it.

A 12th-century fortress containing some of Berlin's oldest buildings.

An imperial church bombed to ruins during WWII now stands as a jagged memorial.

Concerts, art, offices, and a café in what used to be Berlin's first crematorium.

England's most notorious suicide spot.

An ancient water supply dating back almost 500 years can still be found standing in East Sussex.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

Eighty million natural history specimens call this gargantuan museum home.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

Also known as Rye Castle, this 13th-century fortification later became a prison and held one of Rye's most famous criminals.

On the Pakistan-India border the militaries perform an elaborate theater of aggression each and every night.