Before Metro, Washington had a robust streetcar network—and you see the remains of this infrastructure if you know where to look.

This dig site outside D.C. is known for its exceptionally high density of baby dinosaur fossils and dinosaur eggs.

The school tested mustard gas for the U.S. Army during World War I.

Exact replica of the ancient monument, but much, much lighter.

Three abandoned missile silos are hiding in plain sight behind a suburban development in Maryland.

These abandoned waterworks are crumbling into the Potomac River.

Washington's top-secret Cold War-era doomsday communications tower is located in a small neighborhood park.

The fences outside some of South London's estates are made from recycled World War II stretchers.

A measuring mishap led to these artificial stone ladies losing their stomachs.

Legends say that this Art Deco apartment building almost became Hitler's British headquarters.

A traditional American farmhouse plopped in the middle of a Piccadilly courtyard.

One of the greatest movie directors of all time lived and worked in this London flat from 1926 to 1939.

Tombstones and enigmatic inscriptions hide within a vault beneath a popular London arts venue.

A building that survived WWII, possibly on the virtue of its name alone.

An unsanctioned shrine that sprung up outside the late singer's home is causing a stir in London's Highgate neighborhood.

A monolithic monument in Greater London.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.

William Blake claimed to have painted this gothic masterpiece after encountering this nightmarish being in a vision.

The secret wartime bunker built on the platforms of an abandoned Tube station.

London's only public statue of the much-married monarch adorns the gate to St Bartholomew’s Hospital.

The world's oldest optical museum is an odd collection where the exhibits look at you.

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

A recently restored Shoreditch landmark with ties to Jack the Ripper.

There's an exclusive Beefeaters pub hidden in the Tower of London.