This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

A Collegiate Gothic quadrangle that surrounds an 18th century secondary school whose financing came from the likes of Alexander Hamilton and Aaron Burr, among others.

19th century cemetery hidden in Brooklyn's Prospect Park.

Oldest surviving example of a Dutch saltbox frame house in America.

A curious friendship between two inanimate ladies.

Ride the subways of yesteryear.