A beautiful geyser under environmental threat.

The first declared National Monument in the United States.

Despite monuments in other locations, this spot in a South Dakota field is recognized by the U.S. National Geodetic Survey as the center of the 50 states.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

One of the "twins" in these falls on the Snake River was sacrificed for hydropower generation in the 1930s.

Where the famed daredevil attempted to launch himself across a canyon in a custom-built rocket.

Supposedly Satanic numbers adorn this preserved submarine sail.

Home to the deepest rift anywhere on Earth.

Quito's historic, main square dates back to the 16th century.

A stunning Catholic cathedral built by a curve-loving communist in Brazil’s newly created capital.

Massive rock sculptures formed during the time of the dinosaurs still stand undisturbed.

A bright little alley in La Boca is a part of tango history.

A series of waterfalls so massive they straddle the border of Argentina and Brazil.

This red lake 4,000 meters above sea level is home to rare flamingos.

A valley of unique erosion patterns lends to a view like nothing on Earth.

On the outskirts of a desert trading village high on the Andean plain, steel giants have been destroyed by salt winds.

A seemingly endless landscape of pure salt stretches far across Bolivia.

Situated on a sacred Inca site, this 16th-century cathedral took nearly 100 years to build.

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.

The mysterious "Candelabra of the Andes" could represent anything from a god's trident to a hallucinogenic plant.

Visiting dignitaries and Hollywood stars once stayed at this 1920s hotel, alongside ghosts that are said to haunt its corridors.

The Uros people live on floating reed islands in lake Titicaca.

Plundered and left asunder by grave robbers, this ancient necropolis has been painstakingly pieced back together.