This cave holds a surprisingly colorful variety of geological oddities.

The tunnel that runs beneath this former inn was once a hiding place for enslaved people seeking freedom.

A bizarre house filled with an astounding array of collections.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

This museum celebrating the almighty dollar lets visitors literally stand in the shadow of a million bucks.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.