This 4,000-acre restored grassland in northern Illinois is home to a range of native flora and fauna, from clovers to plovers to a herd of bison.

This national park dedicated to the tallgrass prairie ecosystem still displays its military past.

This architectural stunner is one of the few surviving Egyptian Revival theaters in the U.S.

This former nursery supplied plants for the creation of Chicago's largest park.

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

Equal parts record-breaking temple to consumerism and bizarre fun park, it's more than you think it is...

This water tower has been a staple of the Rochester skyline since 1931.

Tour the luxe "glass cage" that inspired and unnerved the architecture world upon its debut.

Burial mounds of prehistoric Native Americans who lived along the DuPage River.

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.

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

The final resting place of two unknown soldiers.