The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

Once the site of the Hawaiian monarchy, this building was originally designed as a palace.

Launchpad for the US military’s dead mouse operation to battle millions of snakes.

This massive wooden building contains a giant Buddha, healing pillars, and tame deer wandering the grounds.

The 10,000 Torii shrine.

One of the world's largest ancient burial mounds.

Elaborate series of tunnels where traces of mass suicide are still visible.

The seat of the lost Ryukyu Kingdom has survived numerous fires and wars over the centuries.

One of the world's largest tanks mimics the experience of watching rare whale sharks, giant rays, and deep sea creatures from the ocean floor.

The century-old bell and clock tower at UC Berkeley is the third-tallest in the world, and has fossils.

This Oakland fairytale kingdom, fiercely devoted to childlike whimsy, was an early inspiration for Disneyland.

A tiny theater hidden in an alley plays a constant stream of short silent films for anyone willing to peer through the peephole.

The grand, column-fronted, sculpture-adorned home of the ambitious digital library.

San Francisco's urban bison herd has persisted in the face of extinction, development, and disease.

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

This lighthouse has been guiding shipping into the Golden Gate since before the American Civil War.

Concrete strongholds stand guard over the Golden Gate.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

It was once the base for a series of domestic terror attacks.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."