Hide from the tourist hordes in these relatively unknown, and unguarded lava caves.

This legendary urban waterfall creates a dazzling display of rainbows.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

More than 2,000 species of tropical plants call this nature preserve and sanctuary home.

These ancient sacred grounds granted amnesty to those who managed to reach them.

This black shoreline is made up of exploded lava particles.

This abandoned church dominates the landscape of a former mining boomtown.

This replica of the Indian spiritual master Meher Baba's tomb stands unfinished in the New Mexico desert.

Located near the U.S.-Mexico border, this park remembers the famous raid of General Francisco “Pancho” Villa and his soldiers.

This fast-food outlet is the only space and UFO-themed McDonalds in the world.

A blacklight journey through a celestial art exhibit.

A museum dedicated to the alleged Roswell Incident.

The final resting place of the living embodiment of the famous Forest Service symbol.

Home of the International Space Hall of Fame.

An ode to the friendship between four Pacific Rim countries.

Get fishing gear and craft beer at this restaurant on the pier.

Stripes of flowers bloom each spring in a 50 acre rainbow of color.

This large collection of tiny things revels in the art of fine machinery well made.

A self-built castle made by a mysterious man.

The state's only comprehensive museum dedicated to the mineral that defined its history and economy.

Tucked away behind an unassuming set of shops is a must-see series of stunning murals.

An inconspicuous footbridge beloved by San Diego locals.

The oldest standing structure in downtown San Diego.

A sculpture of the famous photograph stands on San Diego's "Greatest Generation Walk."