Secluded nice locations to Propose this time of year?

I plan to propose to my girlfriend in just a few weeks and have a couple spots that I think would be great places to do so. I don’t want to draw a ton of attention, she wouldn’t want to either, so if I can find somewhere that’s really nice and quiet that would be great! It will be me and her plus maybe my sister hiding somewhere with a camera.

Cylburn Arboretum is at the top of my list, but they require a scheduling for proposals and then a permit for pictures. And then permission to post those photos anywhere. It just seems overly restrictive.

The Patterson Park Observatory would be great if it was open and we could go up to the top!

Then there’s Riverside Park, Rawlings Conservatory, and Federal Hill but we’ve been to those places already.

My other concern is if any of these locations are still worth going to in this season.

So as you can see, I have a number of spots already in mind. I’m just probing to see if there are any suggestions that would be better, thanks!