Either your place... or the back woods park trail definitely sounds the best to me out of those options...
As far as the park trails... Deep enough in you can get to talking on the way there... get all boned up / teased up while you find a good spot. Should be able to find seclusion enough to not have to truly worry. But there's always that "chance"... so it still gives it that taboo and dangerous flare you might be looking for haha. Just don't get any splooge on your clothes and always keep and eye / ear open ^_~
As far as bringing guys to your place... true discretion is difficult if you're in the closet about it, and that goes for the park trails as well. If you live alone, it becomes a little, to a lot, easier. But either way you'd only want guys over that "have a good excuse to be there" OTHER THAN even the 1% chance that someone could even THINK you're swapping cock sucking fun with him.
That means stick to other "in the closet guys" only, and only after you've built up that illusory reason for them to be there like normal friendship or etc.. Stick to guys that also have something to lose if they reveal themselves and what you two have been doing...Openly gay guys to my experience don't have anything to lose in "that" regard... and are naturally going to be more prone to have loose lips in regards to such matters. Avoid drinkers in all honestly as well.. last thing you need is drunken confessions. (Yes i know... say goodbye to 99% of the "pool of people" when that detail is added in... but that advice comes from experience... are you after true discretion or risk?) I've had a drunken individual go blabbing to "someone HE trusted".
Gotta love when they tell their super trusted friend... then that friend tells the person they "trust most in the world with their secrets"..... see the problem haha.
Moral of the story... discretion is difficult at best. And extremely rare to find unless you're just lucky to my experience.
But location-wise.... park trails... and your place if you live alone, or if you don't live alone, make sure said person has a "good reason" to be there like I said. ^_~