The oldest extant wooden jail in South Dakota and possibly the United States. 

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

An experimental, automotive replica of Stonehenge.

Twenty churches beautifully painted by 19th-century Czech and German immigrants in Texas.

No one is sure why this mysterious tradition started.

The oldest active mini golf course in the U.S. has an elegant Art Deco style filled with lush tropical plants.

Over 100 million years ago, beach-bound dinosaurs left permanent marks on San Antonio's landscape.

A unique cartoon-filled roadside attraction.

Made of giant chains and hung with shackles, this iron cross honors those unknowns who perished under American slavery.

Scale replica of China's ancient terracotta tomb warriors and Forbidden City are the side project of an eccentric millionaire.

A medieval castle in the middle of rural Texas.

Follow the steps, and this roadside artwork will teach you how to dance.

The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

A recreation of the doomed ocean liner in the middle of the Smoky Mountains.

All that remains of the once-booming chain is a single orange-roofed restaurant.

This former theme park in New York's Adirondack Mountains fell into ruin before being resurrected as a state-run campground

The world's only statue dedicated to the greatest Great Dane in comic strip history.

A bizarre house filled with an astounding array of collections.

A serene plaza that commemorates one of the Granite State's most iconic figures.

This modern medieval weapon of war was built to toss pumpkins.

A bygone village occupation lives on via this quaint public chalkboard.

An artist sees trees as a medium for sculpture.

These mysterious petroglyphs in Vermont reflect a troubled history in the treatment of Native American culture.