Commemorating the spot where the famous scientist fed his pigeons.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Elevated freight railway turned wildly successful urban park.

A terrific purveyor of natural history objects and curios.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

There must be a pun in this haystack somewhere...

A large statue of Pope Gregory XIII in Bologna was disguised as Saint Petronius to avoid destruction.

A striking memorial recalls thousands of Bolognese men and women killed fighting fascists in World War II.

An ancient fortification lives on in this Chinese city.

Alexander Hamilton’s creation caused quite a bit of controversy.

This beloved marketplace mascot poops money and grants good luck.

This elaborate towering structure was once famed for its revolutionary height.

Huge masonic hall in Philadelphia with lavishly themed rooms.

Amazingly, this old machine within the Resorts Casino still functions.

This 19th-century Hamptons windmill was once home to modernist painter Agnes Pelton.

One kilometer of thick brass rod laid out before your eyes.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

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.