The oldest functioning mailbox in Spain was installed in 1793.

One of Europe's oldest yew trees has lived more than 2,000 years.

A bookstore dedicated to the intersection of comedy and art.

This castle-fortress is a living example of the transition from medieval defenses to modern fortifications.

An eclectic collection of thousands of items owned by the sculptor Frederic Marès.

The oldest giants in Catalonia are now displayed in a 14th-century Gothic church.

In the middle of a Brussels roundabout, a cargo container balancing on its edge.

A centuries-old bar once frequented by Picasso, Hemingway, and Dalí.

This stone in Lexington honors a formerly enslaved man who fought during the American Revolution.

Ice cream stand, snack bar, and time capsule of milk conveyance.

A memorial to Chinese freedom in the city where American freedom was born.

A gift to the children of Boston, this bronze bear represents playfulness, a spirit of love, and the warmth of big hugs.

This historic Boston building has gone from personal estate to porn theater and back again.

The former site of an all-but-forgotten colonial landmark is now remembered by an often overlooked bas relief.

Created by a local artist, these quirky sculptures each have their own names and personalities.

A men’s restroom became a sandwich shop.

This bronze sculpture was inspired by a photograph of Martin Luther King Jr. and his wife embracing after he won the Nobel Peace Prize.

American revolutionaries and British soldiers alike are buried here in the fourth-ever cemetery in Boston.

The Boston square dedicated to the dark poet who was born nearby.

Statue commemorating the use of ether in anesthesia.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

A luxury hotel constructed out of a former jail.

Former home of an abolitionist couple who escaped slavery and established the most active Underground Railroad stop in Boston.

The Boston home of a conductor on the Underground Railroad.