In the heart of Medellín, an artsy urban complex sets the stage for demonstrations and protests.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

Amsterdam's former hotspot for public executions and dissections.

A public urinal so pretty, it was declared a national monument.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

The largest offshore wind farm in the world would be even bigger if it weren't for some pesky birds.

Graffiti from the 16th and 17th centuries cover the walls of this part of the Tower of London.

This memorial to World War II's fallen airmen shows us the movements of the stars that once guided them.

Never actually a tree at all, this spot was the site of London's public hangings for nearly 600 years.

One of these two land speed record-breaking vehicles went so fast it shattered the sound barrier.

This star-shaped artillery fort protected the mouth of the Thames from the 16th century to the Second World War.

A Roman spa buried deep beneath the City of London.

Fulham F.C. imploded once everyone excised its giant, hated tribute to the King of Pop.

A striking 500-year-old mansion provides an unexpectedly sublime home for live deer and a menagerie of exotic stuffed animals.

The Last Home of an Executed King.

No one is sure what to do with this WWII shipwreck that sits at the bottom of the Thames, still loaded with tons of explosives.

The Isle of Wight’s “Island Line” serviced by former London Underground trains from the 1930s.

Preserved baths in a Victorian-era spa town frequented by the most famous people of its day.

This innovative steam machine was no doubt the most famous of the pioneer locomotives.

A unique tribute to the millions of animals who served and died for the British military.

The largest clown school in Britain offering accredited degrees.