It is located at 9800 Willow Springs Road.
A crowd of people were on hand to check out the new building, which is nearly 18,000 square feet.
The nature center has been a forest preserve icon in Cook County for more than 55 years.
The old school house will no longer be used as a nature center, but it is being restored and is expected to be used as a classroom.
The new nature center has real and preserved animals on display as well as plenty of activities for children.