[WhyDoIThinkThisWay?]

So I have a dare/challenge for you, although it probably won't be the sort to make you orgasm and I am not sure how willing you will be to try it seeing as it is semi-public. As you mentioned you don't have woodlands nearby but hopefully you can still find somewhere suitable.
The dare is to find somewhere publicly accessible, somewhere anyone has access to but rarely goes (such as a spot in the woods) this is where your owner's discretion comes into play for the first time, he will pick the spot, somewhere quiet where you're unlikely to be found (but not impossible).
Next, you strip naked, (Your owner can adjust how little you wear if he feels that you being completely naked is a little too much, again, he should use his own discretion). Then he should bind you to something such as a tree or perhaps best a bench (preferably with your arms and legs stretched out, the more revealing and restrictive the better). Last but not least he should blindfold you, I would also have you use earphones or earbuds but seeing as you are deaf that of course isn't necessary.
Finally, your owner will then leave you alone. He could go for a walk, go for some food, go to the cinema or go for a nice long nap, the choice is up to him, he can do whatever he wants, and go as far as he likes. He could be 10 minutes or 10 hours, letting you dwell in your own thoughts of what could happen. The important thing is that only he knows when he will return for you. (Of course, depending on where you are left and how safe this location is he should again use his own discretion.) I have also realised that perhaps setting up a hidden camera wouldn't be a bad idea, after all, outside of them touching you, if someone did happen to find you then you wouldn't have a clue, they could be stood right in front of you gazing at your body and you would never know. Your owner could check the camera afterwards to see if anyone did ever find you.

Again I know this might not be entirely the thrill you are after so I understand if you pass up on this suggestion or modify it to suit you both better, regardless, good luck, have fun and don't get caught (or do).