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

Join in a Seance at the Swedenborgian Church.

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

Have a steam and some blini at this cafe in a century-old bathhouse.

A strangely angled West Village home is the only monument to an explosion that took the lives of three American revolutionaries.

Phil Mortillaro uses keys to bring art back to the Village.

This simple Manhattan salt house is artfully shaped... well, like a giant granule of salt.

Amid skyscrapers and traffic exists this unique aquatic ecosystem.

This Russian bar-restaurant lies within a three-story underground bathhouse.

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

An institution dedicated to the towering buildings that make up skylines in New York City and around the world.

Finally, you don't have to be a pious Swedish seaman to relax like one.

Though the case is scorched and the buttons half-melted, this hardy handheld gaming device can still run a game of Tetris.

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

A bit of retro transportation flair preserved in the world's largest department store.

Nikola Tesla's former home contains an homage hidden from plain sight.

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.

A dilapidated dock tells the story of Titanic's missed arrival.

Manhattan's Thirteenth Avenue was made on landfill then deliberately destroyed — apart from one small, obscure block.

A hands-on traveling collection of the innovative devices of yesteryear.

Play heads or tails with thousands of different coins.

This narrow shop in the East Village hosts a matchmaking service for the new millennium.