Beautiful mosaics cover the first stations opened on New York City's newest subway line.

This exemplar of modernist architecture is meant to captivate and inspire students of the Cooper Union.

An odd, ancient window that may have once been part of a brutal prison is embedded in the side of New York's Police Plaza.

Touching mementoes from those who didn't make it back from World War I still hang in one of New York's oldest bars.

The oldest living tree in Manhattan comes shrouded in sinister legend.

A hidden "place of interment for gentlemen."

The fanciest public restroom in New York City boasts fresh flowers, art, and a classical music soundtrack.

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

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

One of the last few places in Manhattan that employed a pneumatic systemic keeps it on display.

A celebration of capitalism in Midtown.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

Ride the subways of yesteryear.

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

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

Elevated freight railway turned wildly successful urban park.

The narrowest street in Paris.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

Indents in the pavement are all that remain from a grisly death machine in Paris.

Forever immortalized in concrete, this Simpsons etching was crafted by show creator Matt Groening.

A public fountain that spouts "health water" from a nearby spring.

This little slice of the Netherlands in the Pacific Northwest blooms in a rainbow of color each spring.