A submerged archeological park still holds the wonders of a Roman Sodom.

Architectureal fantasy quarter of Rome.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

A 16th-century horror show built in a lovely Italian garden.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

A terrific purveyor of natural history objects and curios.

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

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

Behind a grungy bodega facade, a Poblano family serves rich, home-cooked meals.

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

More than 250 sakes are available in an izakaya hidden in the basement of a Midtown office building.

Make a tough dinner decision: Octopus wasabi roulette or bull penis?

Bowl in splendor, if you're lucky.

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

Slyly buy a shake in the Parker Meridien lobby.

This semi-hidden Manhattan restaurant is based out of a loading dock.

Great place to have a drink and a bite to eat in an atmosphere laden with New York's Bohemian past.

One of the last Jazz Age "Wonder Theaters" in New York City.

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

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

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

Mysterious 500-year-old tapestries depict a unicorn hunt.

One of only two commuter aerial tramways in the United States.