The largest and best-preserved rotunda in Prague.

A historic and beautiful Art Nouveau chamber in a historic railway station.

A grumpy old water goblin guarding an old mill on the Devil’s Stream in Prague.

A plaque marks the spot where the saint was shoved off the Charles Bridge and into the river.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

The first museum in the world devoted to sexual gadgetry.

Macabre astrological automaton clock dating to the late 1400s.

Three hundred illuminated pillars form an “artificial forest” in Medellín.

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

A 10 million-ton rock once worshiped by the Tahamies Indians, accessed by an astounding staircase.

Ripped apart by a bomb in 1993, the shell of Pablo Escobar's infamous vacation house still stands.

The Andean town where every single building is decorated with a brightly colored frieze.

Two identical statues by Fernando Botero, one blown to pieces in a terrorist bombing, the other donated as a gift for peace.

Home to 23 voluptuous and instantly lovable sculptures by one of Latin America's most celebrated artists.

Building owners can take out tiles for free at this repository for historic building materials.

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

This historic streetcar system has been running since the 19th-century.

Elaborate tile work in this railway station tells the story of Portugal.

Ancient catacombs form the foundation for this Rococo orgy of a church.

A hidden three-foot-wide house separates these two regal churches.

The stunning interior of this Gothic church is covered in ornate gold details.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.