A tiny plaque marks the location of the water source that facilitated the birth of modern-day Boston.

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

Ralph Waldo Emerson spent two years living here decades before it became a Frederick Law Olmsted-designed park.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.

Barça football fans might see the insignia hidden in a church window as a divine sign.

An early 20th-century bullring converted into a modern shopping center.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

This cemetery features modernist statues as strange as its name.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

This water-tower-turned-high-end-apartment building was once the site of an early Nazi concentration camp.

A restaurant and observation deck built in a unique broadcasting antenna.

Berlin's old airport.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The most visited, and possibly most controversial, museum in Germany.

An eerie, derelict amusement park in Berlin.

This wall on a street corner in Lower Manhattan has been a blank canvas for a rotation of renowned artists since the 1980s.

Prove you deserve to be fed by Kenny Shopsin.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.