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

What was once the second largest steel mill in the US is now a sprawling complex of modern ruins.

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.

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

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

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

This cemetery is all that remains of a school for "wayward" girls.

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

A remote hill on a stretch of country road where the laws of physics are defied... or so it seems.

This family driveway also serves as the highest point in Illinois.

An underground wonderland in Iowa.

An amazing collection of scale model ships.

Cemetery featuring rare glass-fronted columbarium.

The subtle science of a master molecular gastronomist.

A speakeasy takes on Chicago's drinking culture.

This shop for all your super spy needs hides an educational secret.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

This morbid, delightful curiosity shop offers everything from animal bones to human teeth.

This whimsical Oz-themed park had a wonderful impact on the surrounding neighborhood.