Scattered throughout London are ancient remnants of the city's former bounding wall.

London's smallest police station is barely the size of a phone booth.

Eighty million natural history specimens call this gargantuan museum home.

An unusual round church in London with a Templar past.

A student driver's nightmare.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

The bank that helped fund the Mexican-American War and the purchase of Alaska met its downfall after helping Augusto Pinochet launder money.

This fertility idol of questionable authenticity inspired an iconic Indiana Jones artifact.

The iconic D.C. restaurant where the Cuban Missile Crisis was negotiated, now a Walgreens.

It was once the base for a series of domestic terror attacks.

Bar full of oddities, specimens, artifacts and homages to the great dime museums of the past.

Railroad officials in the early 1900s sought to spare travelers the sight of Roman soldiers’ private parts.

A tribute to the pop culture icon overlooks this Washington D.C. intersection.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

This statue of the "father of television" stands prominently in the United States Capitol.

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

This statue of one of baseball’s greatest pitchers looks like something out of a sci-fi horror movie.

The grand marble structure next to the White House is Andrew Carnegie's temple to Pan-American diplomacy.

An ear-piercing buzzer calls lawmakers to a vote with a series of long and short rings to form coded messages.

Every drop of D.C. tap water flows through this old waterworks.

Corn-inthian columns with a uniquely American take on neoclassical architecture.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.