If you're not familiar with the Gifts of Evil, you can see the backstory here. This one is a little easier than the first two, though not too much. This is placed in Shawnee Mission Park and meets the guidelines established by Johnson County Parks and Recreation (as much as possible, at least).
If you look this up on an aerial map, you'll see what looks like a tiny airport runway nearby. That's because there's a tiny airport runway nearby. Remote control airplane enthusiasts come out here and fly their planes, using the landing strip provided. There's usually a small contingent of observers on the weekends, so you'll want to be stealthy.
Have fun!