The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

One man's quest to save his town with a trail of record-breaking sculptures.

A giant pair of thick black glasses mark the tragic demise of a trio of rock and roll legends.

A four story, football field-sized, nine-grotto creation made of shells, minerals, and rare stones.

The final resting place of the most famous sharpshooter.

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

Six tiny houses built for working class people form the largest intentional cluster of Wright homes anywhere.

The world's largest talking cow would like to tell you about the benefits of 100% Wisconsin dairy products, if only she still could.

A giant, Gilded Age mansion that once belonged to the beer baron of Milwaukee.

Vikings and Evangelicals have both had a hand in this replica medieval church.

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

Once the largest windmill outside of Holland, with enormous 114 foot sails.

Guns that have been defending San Francisco since 1904.

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

Golden Gate Park's historic collection of plants.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

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.

A portal into the bricked up canal that runs through the heart of Washington D.C.

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

A building shaped like the Army Corps of Engineers logo, because why not?