The oldest bibliophilia club in America, with exhibitions on historic books and graphic arts.

The oldest surviving synagogue in New York City is now a soaring art space.

Once the tallest building in the world and the site of "the highest dinner ever held in New York" this building now holds the most expensive penthouse in the city.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

An unassuming secret door once led to a legendary watering hole.

Become a prohibition rebel.

New York City's smallest piece of private property.

A miniature rainforest is growing inside of a Midtown Manhattan office building.

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

Elevated freight railway turned wildly successful urban park.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

2300-year-old Roman road connecting the empire.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

Commonly acknowledged as the only public monument to the Devil himself.

This hulking behemoth is actually five interconnected towers built in the 1960s.

A small subculture of boat dwellers keep their traditional way of living alive at this Hong Kong Typhoon Shelter.

The world's longest outdoor covered escalator system transports commuters through Hong Kong's hilly terrain.

Though considered an eyesore by some, this boxy Brutalist high-rise plays a significant role in Sydney's past.

A New Zealand communications tower stands as the tallest structure in the Southern Hemisphere.

A centuries-old forgotten underworld lies beneath Malta.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

Visitors dating back to the 1600s carved their marks in the stones of the iconic tower.