A living memorial to the trees London lost during the Great Storm of 1987.

An unusual ode to the late Irish playwright, complete with a squiggly bust and coffin-shaped bench.

A sculpture outside London's oldest cathedral honors the Mohegan chief who died while petitioning the king.

Murals of the wild parties once held on the frozen River Thames.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

The last four extravagant street signs of London's historic banking street.

This one has sailed five times as far as Sir Francis Drake's famous ship.

Installed at a chaotic intersection, this gave London traffic cops a place to hang their heavy woolen coats.

This legendary stone is of unknown origin, and throughout history has been a literal touchstone for British leaders.

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

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

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

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

This South London cemetery holds the remains of more than 15,000 people.

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

Outside a Viking museum sits a modern-day runestone made by a Swedish runemaster using traditional methods.

It houses the remains of a 17th-century version of the Titanic.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

North Korea's massive "hotel of doom."

Pyongyang’s Arch of Triumph is the second tallest triumphal arch in the world.

One of the largest public squares in the world, named after the former DPRK supreme leader.

A former palace transformed into a mausoleum for North Korea's supreme leaders.

A symbol of the Workers' Party of North Korea.

A highly symbolic tower in honor of Supreme Leader Kim Il-sung's personal philosophy.