If you like to swim, summer is the best time to visit, but that’s also when the most other tourists are around. In fact, capacity at the pond is limited - the beach area is pretty small - so if you get there “too late” in the morning, you have to wait until about 3 in the afternoon to be allowed in.

If you just want to visit and maybe dip some toes in the water, October would be beautiful. Early October would be warmer, later October would have more color.

Keep in mind that the original cabin no longer exists; they’ve found where it was, but the wood was used long ago for something else. (Recycling!) You can hike to the site and toss a stone on a big pile of remembrance stones - some people paint messages on them for loved ones, etc.

As you know, we’re lousy with early American historical sites up here. One that often goes unnoticed, though, is Old Yorke, Maine. I took the kids on a group field trip there, and it was fantastic. The staff made sure everything had a hands-on component for the kids. I don’t know what it would be like if you just dropped by for the day, but the organized field trip was terrific.