Located very near the E Broad St parking lot for the Greenway. You'll go "off road", but not into the woods. You'll need shoes with lots of tread, because you'll be going "up". My three year old did it, so I know you can, too.
If you find the cashe, you can keep going up the trail to find a lovely playground, nice walking and bike trails, and plenty of soccer parks. But getting to this cashe won't take long at all. Just be careful. And then watch you head!