This weekend, I was fortunate enough to spend a good two hours hiking at Wild Basin Preserve off of Loop 360. The weather was beautiful, and the hike was meditative and a nice stress-management exercise.
My only advice, arrive far ahead of the sun's departure (moonlight isn't exactly hiking-trail appropriate), grab a trail map and don't hike with an over-confident hiker...getting lost IS possible. The trails on the preserve are over 3 miles long and you're bound to see deer, waterfalls, and walk stream-side for at least a mile. If you don't already love nature, go on a hike, your computer trained eyes and always-on-the-go self will appreciate you.
Admission to the preserve $3 for adults and $2 for seniors and children under 12. Technically, the trail hours are from sunrise to sunset so arrive with enough time to do some exploring.