The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

Try not to get slimed in Tribeca.

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

A crumbling hospital from the 1850s on Roosevelt Island.

A terrific purveyor of natural history objects and curios.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

A historic 1890s architectural masterpiece with an iconic clock tower that, once open to the public, now faces an uncertain future.

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

Originally built for London’s cab drivers, this bright green hut now serves anyone a hot drink or meal.

More than a million titles fill the labyrinthine shelves of this prestigious private library.

This pump on the bad side of Victorian London betrayed a horrifying revelation about the water supply.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

Where condemned pirates met their grisly end at the gallows on the River Thames.

Revel in the Victorian splendor of the world's oldest eating establishment inside a museum.

The 2,000-year-old beam is tucked within the pedestrian entrance to the old London Bridge.

The wooden telephone box hidden away in London's Piccadilly was the original prototype of the iconic kiosk.

This overlooked street light once served as a KGB dead letter box.

This small collection of rare books was uniquely locked up for safe keeping.

A Roman spa buried deep beneath the City of London.

Explore nearly 400 years of English middle-class home life.

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

This artist's home turned gallery/museum preserves the creator's love of "Eastern" influences.