I went to NYU for three years and Central Park became a favorite place to find some peace in a busy city. New Yorkers firmly believe that the park is huge. Sorry my NYC friends, but not only is South Mountain Park much larger than Central Park it's larger than all of Manhattan! Yep, 16,000 acres of nature - right there waiting for you to enjoy it. Not bad huh?
For first time visitors I recommend a drive up to Dobbins Lookout. You'll be at an elevation of about 2,300 feet which will give you a fantastic views of the entire valley. It's a must see on a clear day.
For a nice hike I suggest the Kiwanis trail. It's roughly two miles round-trip with 400-500 foot elevation change.
If you still need more nature after your visit to South Mountain Park or if you'd like to learn the plant names, head to Desert Botanical Garden which is about a 15 minute drive away.
Two tips:
1. Bring water.
2. Download a trail map to your phone before your hike. You can get pdf maps at http://phoenix.gov/parks/trails/locations/south/hiking/