The site of the first "historically true" UFO encounter in the U.S.

A 16th-century Andalusian palace.

World's second largest particle accelerator, where nature reveals its secrets.

An exhibit of items from the mental institution where Mary Todd Lincoln lived after her son conspired to have her committed.

This house renovated by Frank Lloyd Wright was the centerpiece of a lavish 20th-century estate.

Arguably the best example of an authentic Dutch windmill in the United States, rivaling its counterparts in the Netherlands.

A hidden grotto on the grounds of the Kane County Government Center.

A replica viking ship from the Chicago World's Fair is still in dry dock in an Illinois park.

This overgrown Illinois water park offers a whole new type of adventure.

People escaping slavery passed through the oldest house in Lombard, Illinois on their northbound journey to freedom.

Cold War missile launch site which has been converted to a public park.

A tribute to one granddaughter's old apartment which now represents the whims of each visitor.

Tucked away amongst townhomes lies a restored, early 20th-century tea house and garden, the only remains of a historic estate.

This elaborate Hindu temple is located in a Chicago suburb, but looks like it was transported directly from India.

A waterfall 600 ft. inside a mountain, once the bane of gold miners, is now a spectacle of nature.

One devoted couple has donated multiple recreations of Michelangelo's sculptures to this South Dakota town.

South Dakota's oldest operating brewery is housed inside a historic firehouse.

An entire city block built completely out of petrified wood.

Yes, this monument is aware that it is about 20 miles away from the actual center of the United States.

Every president in history is immortalized in bronze in downtown Rapid City.

This geodesic gallery holds a collection of painted spheres that make traditional canvases look lazy by comparison.

A striking sculpture built to honor the women of the Lakota and Dakota Nations.

The ravine where Jesse James supposedly performed an impossible jump to evade capture.

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