Central America's deepest lake is actually a volcanic caldera, surrounded by three volcanoes.

These steeply terraced ruins are a stop along the Inca Trail to Machu Picchu.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

This Peruvian canyon is filled with geometric salt pools that have been being harvested since the Incan empire.

Huge stone depressions which may have acted as an Incan agricultural experiment.

Built on the remains of one the Incas’ most important gathering spots, this square keeps the spirit of a fallen empire alive.

Take a dip in the world's largest mineral hot springs pool.

Hundreds of Buddhas in a re-discovered Indonesian temple.

This massive complex is made up of hundreds of smaller temples that date back to the ninth century.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

A statue built to honor the elite soldiers who fought for Latvia during World War I.

A preserved oak tree about 3,500 years old found in Riga, Latvia.

This charming Latvian lane doubled as Baker Street on the Soviet Union’s version of Sherlock Holmes.

The oldest housing complex in Riga is a mini timeline of architectural trends.

The statue of a legendary giant who carried Christ and shouldered the world's sins.

The final resting place of the great navigator, or maybe his brother.

Home of the Large Hadron Collider and the birthplace of the World Wide Web.

This massive subterranean fissure is known as the "underground Grand Canyon."

One of the best-preserved Roman amphitheaters is still used today, but for less brutal events.

Inside this small chapel tucked away in the forest is one of the most well-preserved Danse Macabre frescos.

Bridge that died in war and was resurected.

A former bank seized as a sniper vantage point during the Bosnian War is now a secret graffiti art gallery.

The sad remains of a monument to martial arts legend and movie star Bruce Lee—in the middle of Balkans.

A field filled with carved medieval tombstones called stećak.