The only retired U.S. nuclear missile silo that is open to the public.

Every weekend, people gather here for a brief chance to see their loved ones on the other side of the United States–Mexico border.

The world's largest outdoor organ is played weekly by one of just two civic organists in the U.S.

One of the largest trees of its kind in California.

An ode to the friendship between four Pacific Rim countries.

The classic Atari game's iconic aliens have invaded downtown San Diego.

This little blue house pokes out over the campus of UC San Diego, seven stories high.

One of the largest open-pit copper mining operations in the entire country.

A secret fresh water spring for animals and humans alike hidden along the most famous road in the United States.

A couple turned their front yard into an artistic masterpiece.

An inconspicuous footbridge beloved by San Diego locals.

A cabinet of curious mathematical models and old calculators.

The biggest solar telescope in the world helps reveal the secrets of our sun.

This 40-room dwelling tucked within a cliff was built by the basin's prehistoric residents.

The fading, forgotten remains of a once bright and booming factory.

A mysterious spirit totem at the edge of Navajo lands.

Thousands of Mexican Free-Tailed Bats soar around an abandoned storm drain at sunset each summer.

In Tucson a giant metal snake helps pedestrians cross a busy highway.

One of the world's largest telescopes, stares into the night sky with two huge mirrors.

An artificial crater field that trained astronauts for lunar exploration.

The largest natural travertine bridge in the world is nestled in a small canyon in central Arizona.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

Ancient pueblos built into the base of a natural canyon wall.

A motel dedicated to Southwestern nostalgia.