Things to do in & around Kingston Aug 17-21

Hi all! Me and my teenage kids will be in the Kingston area for a couple days next week (August 17-21). I'd love your suggestions for interesting things to do! We are not unfamiliar with your lovely town; we've been there a couple times before. We've been to Fort Henry, taken the ferry to Wolfe Island, and checked out the prison museum.

Are there any neat events happening during that time? Cool natural areas to explore? Neat indoor things in case it's raining buckets? My kids like rocks, animals, nerd stuff, vintage/antique/old stuff, etc.

Thanks!