Stone Age solar temple is aligned with the sun on each equinox and solstice.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

Home to the infamous "Typhoid Mary" and the worst loss of life in New York's history prior to September 11, 2001.

Built as a gift to the hottest tastemaker of the time, these hidden quarters remain an Art Deco showpiece.

The beautiful tunnel that ran from the lobby to Penn Station is still hidden underneath 34th Street.

Manhattan's lighthouse, erected at the insistence of the unsinkable Molly Brown.

New York City's only preserved family home from the 19th century.

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

This abandoned subway station can still be seen on regular commuter trips.

Bowl in splendor, if you're lucky.

Reverend Jen's unique museum/living room showcases her troll collection.

A masterpiece of LGBT art has been restored in what may now be the most valuable restroom in America.

Wine bottle sculpture with a ship's stateroom inside.

A dark, dank room in subterranean Manhattan was the site of a ghastly murder.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

Plot your trip through the city on the sidewalk.

The oldest house in Manhattan is now a museum that remembers the home's sordid history of scandals, vice-presidents, and ghosts.

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

Deep under Manhattan is the largest construction project in city history. So far, the project has taken the lives of 23 workers, or "a man a mile."

A WWI fighter plane and turn-of-the-century penny candy shop are among the unexpected features of this Financial District building.

For over 30 years the walls of this Harlem schoolyard have been a gallery of street art by "Kings and better."

A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

A living archive of urban activism and space reclaimed.

A hidden "place of interment for gentlemen."