I'd like to preface this post by saying that I'm a huge fan and even a member of the Morton Arboretum in Lisle, IL. Yet I wholeheartedly disagree with writer Pamela Dittmer McKuen that the arboretum's 36,000 sq. ft. Visitor Center is a "contemporary prairie" structure. Designed by David Woodhouse Architects, this gorgeous building is at best a fine example of a modern take on the Usonian style. It has a low, horizontal design and is accented by a cedar, limestone and glass facade. If you live in Chicagoland and haven't been out to see it, you need to go for a visit on your next available weekend!
These were the best shots I could find online and were taken by Bill Timmerman of Timmerman Photography, Inc.: