Enormous lake at the bottom of a unique cave system.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

An overlooked memorial honoring the local Washington residents who died in World War I.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

The most accurate timepiece in the world.

Perhaps the most scandalous statue of America's first president.

There’s a hidden military meme engraved on the World War II Memorial.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

Home to items never before seen by the public.

A grassroots community effort in the 1970s led to the creation of this beautiful garden full of delightfully whimsical exhibits.

This massive store is home to an eccentric collection of vintage, retro, and peculiar goods.

This hollow steel globe is the second-largest in the world.

You can find America's highest suspension footbridge at Grandfather Mountain in North Carolina.

Andy Griffith's hometown has made itself up to look like the fictional town of Mayberry.

This Transylvania County city is home to a rare white squirrel population that is descended from an escaped carnival animal.

An abandoned village that doubled as "The Hunger Games"' post-apocalyptic wasteland is up for grabs.

A piece of outsider public art accompanied by a strange urban legend.

A bronze of the man in all his sinewy glory celebrates his longtime connection to the Ohio city.

This Czar-funded, onion-domed, lavishly muraled Orthodox Church played a starring role in "The Deer Hunter."

The home made famous by the 1983 holiday classic is now a perfectly preserved shrine to the movie.

The world's tallest doric column is this Ohio monument to a naval victory in the War of 1812.