The "Seinfeld" diner.

Plot your trip through the city on the sidewalk.

This building features dozens of faces along its facade, although one is a bit chilling.

Once home to one of the oldest banks in the world, this building is also where Marco Polo's famous travelogue was written.

This effigy of Peter the Great is greatly disproportionate.

These steps offer a breathtaking view of one of Europe's most besieged fortresses.

Hidden along this old street in Antwerp is a surreal monument of a bronze arm sprouting four hands.

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

An ancient Roman temple first dedicated to an emperor's wife is now a church.

A prestigious learning institute of old Shanghai.

Formerly known as Saville Theatre, this mid-20th-century entertainment hub includes an ornate frieze.

Stuck in the arcade of Casa Isolani are three arrows of mysterious origins.

Rediscovered in 1992, this abandoned medieval village once flourished by fishing and piracy.

A dilapidated dock tells the story of Titanic's missed arrival.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

Manhattan's lighthouse, erected at the insistence of the unsinkable Molly Brown.

Possible relics of the ancient Roman city are hidden in this restaurant's façade.

A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

Twice a day one of these tragic bronze mariners drowns with the tide to remember all those the sea has taken.

The home of the first American-born saint is one of the only curved buildings in New York.

Unrepaired walls from a 1920 anarchist bomb attack.

This anonymous businessman sculpted in bronze became an enduring memorial after 9/11, and had been mistaken by rescue workers for a survivor in the rubble.

On the Hudson resides one of the largest clocks in the world.