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.

Concrete strongholds stand guard over the Golden Gate.

A Norwegian-born sculptor created these soaring guardian angels at the entrance to Hoover Dam.

Across this single-file rope bridge is what has been claimed to be the edge of continental Asia.

A giant scale model giving a sneak peek at what urban planners see for Shanghai by 2020.

A son-and-daughter meat market, hawked by mom and dad.

Rivers of cattle blood gone, a strange Escheresque building remains, the last of its kind.

The once highest point in China blends symbolic design with a kick of adrenaline.

The largest retailer of seashells in the world.

One-time winter retreats of prolific inventor Thomas Edison and his friend Henry Ford.

A massive tribute to this small county's top agricultural product.

A real (but thankfully not live) missile stands tall as a monument to the United States military in the small town of Cordele.

This funicular railway rumbles along for a mile up the nearly vertical face of Chattanooga’s Lookout Mountain.

Only known mainland rookery of the threatened Stellar sea lion.

This unassuming cheese empire in rural Oregon churns out more than 150,000 pounds of cheese each day.

A massive sea stack famous for its appearance in The Goonies.

A Roman-style column in Oregon hides a spiral staircase inside.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

This extravagant Art Nouveau rest stop features a million-dollar view of the Columbia River.

10,000 flowered plants bloom in the City of Roses.

One of the smallest towns in the United States.

The world’s largest truck stop includes a barber shop, chiropractor, and a huge museum with antique trucks.

A place of great reverence for Trekkies everywhere, a hero's future birthplace.

Residing quietly in suburban Maryland, this tree has a star-powered history and was grown from a seed that journeyed to space on Apollo 14.