A grand New York post office that is home to mailman Santas, scraps of postal history, and a pneumatic mail system.

The only subway station in the city that still makes use of gap fillers.

A touching tribute to the "Queen of Soul."

Fake subway tiles were installed to cover a design that resembled the Confederate flag—it's unclear if the resemblance was intentional.

Two large-scale sculptures of Adam and Eve greet visitors in the nude at the Time Warner Center in NYC.

Stunningly detailed mosaics in a New York subway station bring life to the Weimaraners of artist William Wegman's work—and to thousands of commutes.

This curved Manhattan building was built to house the opulence of John D. Rockefeller's oil empire.

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

This Dutch Colonial home is the oldest remaining farmhouse in Manhattan.

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.

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

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

The oldest operating apothecary in the US has treated everyone from Thomas Edison to Mark Twain.

Try not to get slimed in Tribeca.

Famously misunderstood wonder of the ancient world

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

This stunning concert hall has become a symbol of Iceland's national recovery.

Travel deep inside of Europe's second largest glacier in the world's largest man-made ice cave.

This natural Icelandic fissure allows divers to swim right between two volatile tectonic plates.

Walk in the footsteps of the gods and straddle two tectonic plates.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Medicinal spa created with the discharge from a geothermal energy plant.

The most famous location in China was home to whole dynasties worth of imperial rulers.