The second largest waterfall by volume in the U.S., Willamette Falls is outdone only by Niagara in the amount of water that is pushed northward.

Multiple waterfalls and several historic CCC buildings anchor this state park in Oregon's Willamette Valley.

The only house in Oregon designed by the famous architect, Frank Lloyd Wright.

The only building in the western U.S. designed by the Finnish architect Alvar Aalto.

World's largest porcine hairball sits in a collection maintained by Benedictine monks.

Each of these gorgeous, intricately decorated rooms is painstakingly crafted to the scale of 1 inch: 1 foot.

The original vault that held the president's remains still stands, empty, not far from where he was finally buried.

Oversized statues are just the tip of this nostalgic Americana roadside attraction.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

When you visit his grave, be sure to rub the Great Emancipator's nose for good luck.

Abraham Lincoln's likeness rests at the top of this giant totem pole.

This diner serves Route 66 nostalgia and what it claims is the 'original' hot dog on a stick.

The rogue roots are gradually consuming some of the historic marble grave markers.

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

This stately mansion, built in 1787 by America's first Secretary of the Navy, is rumored to be one of the most haunted buildings in Washington, DC.

Before Metro, Washington had a robust streetcar network—and you see the remains of this infrastructure if you know where to look.

The site of the climactic scene from the classic horror film is now a historic landmark.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

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

The Lincoln Memorial has inspired many, even though a word on the inscription appears to be spelled incorrectly.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

One of the last mosaic tile facades found in the city.

Washington's iconic carousel has a nice piece of Civil Rights history.