Or.....Knot in Tree - a hole/opening in a woody perennial plant, typically having a single stem or trunk growing to a considerable height and bearing lateral branches at some distance from the ground.
This could be a "quick park and grab" or a "look at all those cars, gotta come back" type cache. Please be sure to use stealth and replace as found. Add natural cover as needed to conceal from local Muggles. Cache responsibly. Play fair. CITO. Enjoy.