The massive, incredibly rare instrument is over 11 feet tall with a range so deep it goes lower than humans can hear.

Originally conceived as part of a proposed Arizona State Capitol building in the 1950s, this structure built in 2004 stands as a monument to the architect's legacy.

There was a top secret plan during World War II to seal a group of soldiers inside the rock.

An awe-inspiring mosque in Morocco with one of the tallest minarets in the world.

The notorious Wild West outlaw was raised in this unassuming abode.

This ancient cave is home to a museum, bar, and is filled with fluorescent minerals.

These mid-century motels once housed the workers who built the Glen Canyon Dam.

More than a century old, this trading post resides in the Navajo Nation.

An exquisite collection of fairytale conveyances that puts most car museums to shame.

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

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

With a facade that measures just 107 centimeters, this five-story building is one of the skinniest in Europe.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

The discovery of these rare, ancient artifacts led to the creation of a new museum.

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

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

A cemetery dedicated to the mountaineers who perished climbing Mount Aconcagua.

These small sculptures pay homage to the lovable star of an iconic Argentine comic strip.

The narrowest house in Buenos Aires is less than 10 feet wide.

A mysterious architectural gem in one of the most elegant areas of Buenos Aires.

105-foot wide giant metallic flower blooms anew every day in the heart of Buenos Aires.

A gateway to a mysterious network of underground tunnels.

This historic stadium was built to host the first-ever FIFA World Cup.

An epic sculpture depicting a wagon and straining oxen.