Kelly's Island. - Ride the ferry over - Rent a golf cart to drive around the island - Walk over unique rock formations carved out by glaciers - Swim in the lake on a beach near the campground - Rent bikes to ride around the island
South Bass Island State Park : Put-in-Bay, Ohio = Perched atop the white cliffs of South Bass Island, this unique 33-acre park is a scenic landmark when viewed from the water, and in turn affords visitors great views and access to Lake Erie • The wooded campground and serene lakeside picnic area offer a quiet retreat from the bustle of Put-In-Bay • South Bass Island's companion park, Oak Point, offers facilities for boaters and picnickers close to the heart of town
Put In Bay "Put-In-Bay is less...wholesome, I guess, than Kelleys Island, but it's still pretty kid-friendly. They have a butterfly house there that my daughter was wild about, and she loved "mining for gemstones". She was a few years older than your kids (I want to say she was six the first time we went?) but there were lots of younger kids around. There's also kayak rentals, though Kelleys may have that, as well. It's much more commercialized than Kelleys, and can be an expensive trip."