One of my all-time favorite places in the Chicago area is the Chicago Botanic Garden. The Garden consists of nine different islands, and was established as a physical property in 1963 with 300 acres. You can visit their website here: http://www.chicagobotanic.org/info/index.php
My favorite location within the Garden would be the Japanese Islands. I enjoy wandering through these two islands at any time of the year. Summer is, of course, the ideal time to visit the Garden in order to see the majority of the plants, trees, and flowers in bloom, as well as to enjoy the waterfall near the entrance of the Japanese islands.
Here are some fairly recent photos from the Garden.
Shoin House - Japanese Garden Winter. In addition to the beautiful landscaping on the Japanese Islands, there is also a Shoin House and a couple of Zen gardens. The Shoin House is only occasionally open; one weekend, a man was there to interpret the house's purpose and history for visitors. The front of the house opens into a small private garden, while the back opens to a small lake.
Shoin House - Japanese Garden Early Fall. Another season and another view of the same house. It's so simple and interesting at the same time. As is customary with the Japanese aesthetic, the rocks in the water behind the house symbolize islands.
Pond - English Walled Garden. On this day in August, everything was so lush and verdant. I would love to live in such an environment.
Pond - English Walled Garden (detail). This is a detail from the pond in the above photograph. I took a close-up picture because I loved the form, the reflection in the water -- just everything about it.
Arbor - Rose Garden. This was taken in the late summer on an overcast day. I think it really does evoke a feeling of the end of summer when all begins to fade.
English Walled Garden. I took this photograph during the summer. It wasn't interesting enough to me, so I applied a feature in Photoshop to give it the appearance of a watercolor.