If you do the clickity on the link you'll find out that it is quite a vast piece of land in the township of Lisle, IL, hosting trees and shrubs from all over the world. For $11 a person (adult price) one can stay on the premises till its closing at sunset. It is trailed with one way paths for cars with a no-rush speed limit of 20 miles per hour, which is great if you want to take the car half way and then get down and walk in one of the walk-only trails around the main paths.
Hubby and I got snap happy and took about 70 pics, and we liked quite a few of them. We hope to go back in the spring when the trees will be blooming again - I don't think that it'll be of much interest in the winter other than for the evergreens.