Beneath the southern end of the Golden Gate Bridge is the “Gibraltar of the West Coast,” a fort built to protect the San Francisco Bay from naval attack.

Guns that have been defending San Francisco since 1904.

The key to turning shifting dunes into the green oasis of Golden Gate Park.

Inside this museum, the history of the Walt Disney Family empire is on full display.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

A tribute to a great Texas blues musician.

This wildlife refuge is home to more than 200 species of birds, as well as monkeys, lizards, and other wildlife.

In Costa Rica's cloud forest, the roots of a woody ficus create a botanical bridge.

An excursion train traverses a picturesque red-rock canyon along the Verde River.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

This huge dam across the Colorado River caused an armed standoff between two U.S. states.

The interior of the Overlook Hotel in "The Shining" was based on this Yosemite original.

Behind this beachfront shop lies a spectacular, colorful sea cave with an equally colorful past.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Austin’s local mountain isn’t really a mountain at all.

Some of the best pastries in "the Czech heritage capital of Texas" come from a gas station off I-35.

A free, canine-friendly alternative watering hole near the more famous Barton Springs.

Belly up to the bar in Cowtown, don't forget to buy some boots.

Home to an endangered salamander, a full moon celebration, and a large spring-fed outdoor swimming pool.

Visitors can walk over the largest concentration of Columbian mammoths to have died from one event.

A tribute to the life and work of the beloved "Peanuts" cartoonist.