A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

Hidden in an ordinary Midtown building is a one-room museum dedicated to the greatest escape artist.

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

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

The world’s oldest and biggest bookstore stocking only mystery, crime fiction, espionage, and thrillers.

Order scoops of pandan, lychee, and black sesame at this family-run institution.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

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

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

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

A terrific purveyor of natural history objects and curios.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

One of the now-less-hidden floral gems of the "Emerald Necklace."

A morbid secret lies hidden within the beautiful walls of the Boston Athenaeum.

This Boston medical museum features the skull of the famous medical case of Phineas Gage.

An enormous, inside-out glass globe built in 1935.

This upscale streetwear store is hidden behind a fake Snapple machine in the back of a deli.

The most photographed house in Maine looks good enough to eat.

The crumbling remains of a 19th century fortess.

Despite the ever pressing encroachment of urban sprawl this grand New Orleans manse still stands.