Hidden beneath the streets of London is a secret subway that only carried mail.

Winding paths and ramshackle mausoleums in the oldest "park cemetery" in London.

Eighty million natural history specimens call this gargantuan museum home.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

This exclusive resort has completely covered a tiny Balkan island in a 5-star warren of guest rooms.

A tiny church on a man-made island in the Adriatic.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

A curious little museum dedicated to the furry feline in the cat haven that is Old Town Kotor.

Bronzes and busts that once stood in the city's main squares are now relegated to a small hidden courtyard.

A fascinating little project dedicated to preserving the charming historic doors of Durrës.

One of the best examples of a Byzantine period monument in Albania.

In the heart of Tirana, this underground nuclear bunker has been transformed into a museum.

A museum dedicated to secret surveillance.

The largest Roman amphitheater in the Balkans once held over 20,000 people, but managed to lay hidden for hundreds of years.

What happens when you cross a mayor and a painter?

Hundreds of thousands of concrete bunkers crowd Albania long after the fall of Communism.

An Albanian monument to the Communism that nearly crushed the country is now a crumbling wreck.

The Boston square dedicated to the dark poet who was born nearby.