The site where hundreds of Greeks were tortured by the Nazi secret police is now a cosmetics store.

This gem is often wrongly overshadowed by the larger, newer Metropolis church in Athens.

This small 16th-century church in Athens is almost entirely surrounded by a modern building.

Where commuters walk through remnants of an ancient Greek necropolis.

The ruined doorway is a portal to the building's turbulent and torturous past.

This mystical orb covered in strange symbols is thought to have been used in ancient Greek magical rituals.

An ancient octagonal weather station named for the eight Greek gods of wind.

A sharp sculpture made of thousands of pieces of jagged glass.

The Tudor-style cottage in the middle of the square is not quite what it seems.

This churchyard arbor is surrounded by hundreds of gravestones placed there by author Thomas Hardy.

Black cat statues guard this temple-like Egyptian revival factory.

This 1920s Dutch barge is now a floating bookstore.

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

A historic London pub with prison cells in the cellar and a "spy room" on the second floor.

The Florence Nightingale Museum is home to the famous nurse's most treasured possession: her beloved pet owl.

An unusual round church in London with a Templar past.

A rocky sea serpent hides caves, blowholes, and a spectacular natural bridge.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

The final resting place of many of Germany's most famous communists.

Super-heavy Nazi architectural experiment.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

Deep under Manhattan is the largest construction project in city history. So far, the project has taken the lives of 23 workers, or "a man a mile."

Visit the site of a subway powered by nothing more than air--and lots of it.

The rotting skeleton of a shoreside fun fair that was destroyed by fire and storms still haunts the Brighton ocean view.