19th century museum with an eclectic mix of curiosities, from Egyptian artifacts to items on archery history to the skull of the world's oldest horse.

Dating back almost 400 years, the oldest public collection library in the United Kingdom was once the study hall of Karl Marx.

This subterranean oyster house has been the pearl of Grand Central Station since 1913.

Built hundreds of years ago this downtown iron barrier once protected a much despised king.

A modern zoetrope on the New York City subway.

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

Behind a bodega is a small museum of relics and ephemera showcasing the history of New York.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

New York City's smallest piece of private property.

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

Read a book next to a Midtown waterfall.

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

Elevated freight railway turned wildly successful urban park.

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

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

One of the last remnants of the city's Chinese nightclub scene is now a dive bar selling killer mai tais.

Early prototype for Frank Lloyd Wright's Guggenheim.

A library built during San Francisco's pioneer times is a student's retreat, bibliophile's sanctuary, and chess player's delight.

Longtime headquarters of controversial boys' club for the world's wealthiest and most powerful.

A hidden subterranean installation offers a view of the sky.

San Francisco's oldest surviving monument and meeting place for 1906 survivors.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

The oldest burial ground in the city, final resting place of city founders, Ohlone natives and murderers alike.

Nestled in the heart of San Francisco’s bustling Financial District stands a unique homage to the Mayan and Beaux Arts.