On the wall of this medieval walkway, a symbol of the Spanish Inquisition.

Possibly the oldest church in Barcelona, this basilica has its pagan and Christian mythologies all mixed up.

This fountain was designed to honor the man who helped bring water to Barcelona.

One of Antoni Gaudí’s earliest buildings, built between 1886 and 1890 for the industrialist Eusebi Güell.

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

Sink your spoon into a luscious crema Catalana at this former urban dairy farm.

This award-winning men's bathroom was just too beautiful to not allow women to see.

A creepy sculpture of a decapitated head invites viewers to see St. Louis through its empty eyes.

A plaque on the side of a parking garage marks the burial place of a great Ottawa chief.

One of the world's earliest skyscrapers.

An abandoned factory along the Mississippi coated by a giant mural.

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

The site of detentions and torture under the Pinochet regime in Chile is now a memorial.

From Iggy Pop to David Bowie to Nick Cave, this regal music studio has served some of the all time greats.

After a nearly successful attempt on Hitler's life, the conspirators met their fate in the courtyard of this Berlin building.

The site where a plot to assassinate Hitler was planned—and its conspirators were executed—is now a powerful memorial to the German resistance during World War II.

An astonishingly accurate water clock that doubles as an hourly spectacle in this Berlin shopping area.

An imperial church bombed to ruins during WWII now stands as a jagged memorial.

A thin golden line commemorates the deadliest terrorist attack in recent German history.

A memorial to the monk who set himself on fire to protest the persecution of Buddhists in Vietnam.

Meant to be a lavish presidential home, the palace became a symbol of the fall of South Vietnam.

This French colonial post office is arguably the grandest in all of Southeast Asia.

A small 12th-century temple surrounded by waters believed to have curative properties.

A battle between nature and architecture in the Cambodian jungle.