A series of concentric circles represented a bold new experiment in socialist urban planning, and it notoriously difficult to get around.

This striking memorial is one of Estonia’s most controversial Soviet leftovers.

The oldest continuously operating pharmacy in Europe.

This 16th-century monastery was founded to cloister the daughters of wealthy local families.

A Christian monastery stands on what was once a holy Incan temple.

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

An Inca spa, military outpost or maybe… both?

The sophisticated hydraulic system of the Nazca civilization.

This geometric feat is a testament to the Incas' mesmerizing architectural abilities.

This metal tower in the desert provides views of a handful of Nazca geoglyphs.

A backdoor to Machu Picchu that only the most foolhardy infiltrator would attempt to breach.

Thousands of colorful pirogues showcase ingenious craftsmanship at the largest fishermen port in Nouakchott.

This 18th-century tower is locally iconic.

The ruins of a pre-Columbian fortress city so secure it held off the Spanish conquistadors for over 20 years.

A forest park outside Tallinn full of architectural and artistic curiosities.

This historic, palatial theater is now one of the world’s most beautiful bookstores.

Estonia's largest creative city is a vibrant bohemian hub located within a former industrial complex.

Legend says lovers who hold hands while venturing along this stone jetty and kiss at the end will remain together forever.

An ancient forest of the Paleocene Age turned to stone.

A brightly colored natural bridge formed by mineral-rich hot springs high up in the Andes.

Locals visit this abandoned train tunnel where a man took his own life to ask favors of his spirit.

This Soviet-era "closed town" was a top secret uranium producer often left off of maps.

This space-age looking obelisk rises over a city in the rainforest, meant to resemble the local castaña tree.

The rusty hull of this 1899 ship serves as a tribute to explorers of the bottom of the world.