Fantastic views and thousands of love locks.

Carved fountains poignantly placed in parks and in front of special monuments.

From Nazi chemicals to the CIA, this architectural marvel has played a fascinating role in German history.

The entrance to this Frankfurt subway station looks like an old tram car crashed into the concrete sidewalk.

This Welsh hotel is the spiritual home of the British 1953 Everest expedition, the first successful ascent of Mount Everest.

A real-life Professor Snape once taught in this Welsh university building, which students of course nicknamed “Hogwarts.”

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

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

A brush maker used his factory to protect blind Jews from the Gestapo.

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

Tiny memorials honor individual victims of the Holocaust.

A slice of central Asia in the middle of Berlin.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

A restaurant and observation deck built in a unique broadcasting antenna.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

London's smallest police station is barely the size of a phone booth.

England's most famous front door has an accidental doppelganger.

The pretty iron lamp is a reminder of the architecture underneath London's streets.

One of the few remaining examples of 19th-century London’s attempt to clean up its reputation.

An unusual round church in London with a Templar past.

Buried for centuries, this hidden cellar is all that remains of London's medieval Whitefriars Monastery.

Dictionary Johnson’s favorite feline.

The taxidermied remains of a once-great parrot.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.