A six-ton, 12-foot-tall concrete prairie dog is touted as the largest in the world.

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

A French chateau, failed utopian community, odd museum, and Stonehenge replica in rural Washington State.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

This was once the home of Gahan's Saloon, Denver's most storied speakeasy.

Someone loved this song enough to carve all of its lyrics onto a tree trunk in a Berlin park.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

Statues of Ramona Quimby, Henry Huggins, and Ribsy the dog in the park where their adventures "really happened."

This large maar crater in Oregon is the bigger brother to Hole in the Ground.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

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.