S&SwDtB: It would be a while before I can come up with a less muggleable cache container, so we'll just close this one out. If anyone happens to be interested in the answer to the puzzle, the place a parent might rest was a bench, and the mark you added made a "benchmark". The closest was FIELDS, which, if you walked across it, took you into the woods, past a large oak tree, to a two-trunked oak, whose trunks twisted around slightly as it went up.
Congradulations to everyone who found it, and aplolgies to those of you who found the puzzle too difficult.