Final resting place of Geronimo, Quanah Parker, and the first atomic gun ever fired.

Potential high level nuclear waste storage site for the next 10,000 years and beyond.

The largest man-made crater in the U.S. marks the spot where we once tested mining with nukes.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

The world's largest military aircraft cemetery.

The highest point in Washington state is a volcano covered in glaciers.

One small town in the Pacific Northwest transformed itself into a Bavarian-themed tourist destination.

An obscure waterfall that looks like something out of a fantasy novel.

Rustic natural hot springs in the deciduous rain forest.

This famous bridge twisted itself into oblivion, but not for the reason you might think.

This working class sculpture pounds his hammer all the livelong day.

A 100-year-old purveyor of curiosities, curios, and kitsch featuring mummies, shrunken heads, and a Fiji Mermaid.

This titanic oil company sign is a reminder of the Americana boom of the 1970s and also its commoditization.

What was once a presidential estate is now an exotic menagerie and home to the Budweiser Clydesdales.

At 207 feet, one of the world's longest continuous escalators.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

A former major munitions plant that has been converted into a sprawling art space.

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

Every drop of D.C. tap water flows through this old waterworks.

The bridge's highly-contested plaque (once again) honors Confederate President Jefferson Davis.

The bank that helped fund the Mexican-American War and the purchase of Alaska met its downfall after helping Augusto Pinochet launder money.