In the woods in an undeveloped wooded area in my town. I would walk the perimeter around and around until I was fairly sure it was not ‘populated’.
I was prompted the first time after I found a discarded plastic sack with about 10 dirty magazines in it. I knew of a clearing that was quite unknown within, that had a larger 10 foot high rock on one side, a small grove of small evergreens in a semi-curve coming from around it, and some other smaller pines and high grasses. There was a flat stone like a ledge near the larger rock, remarkably free of bugs etc. I took the magazines in there and stashed them, later after on more lap around went back, ( this was early summer). I was feeling bold and scared, but horny as fuck, I got the sack, looked through all the magazines while caressing my aching cock through my sweats. Eventually I was too horny to care if I was seen. I took them and my underwear off completely, stiff cock dripping and lustfully throbbing with pleasure. I focused my desire in several centerfold spread pussies and one LEG SHOW that triggered me, possibly for the first time, calling me a masturbator. Once I was half naked, I think I lasted maybe 5-6 minutes more until I spurted a big load of cum. I remember the intensity of the pleasure. I collected the magazines and put them away in the sack, walked back to where I had locked my bicycle, and went home WITH THE SACK. That was my jack off stash for about a month. Several times I went there without magazines just to toss one off on my way to a friend’s house.
Also about a year later, I took one of my first girlfriends in there to make out and feel her up, fingerfucked her and she jerked me off. Pretty soon we fucked one time in there. But that was literally weeks before they bulldozed it all to put up a nursing home.
Source: Where is the craziest place you’ve masturbated? – Onania Masturbator Forum