Make sure you visit al johnson's in sister bay, it is a swedish restaurant and the roof has grass on it, then goats come out and eat and walk around on the roof. Penninsula State Park-like Jim said, great biking, hiking, you will also probably want to climb the tower that overlooks the bay, you can also walk up a Tower in Potawatomi state park outside of Sturgeon Bay, but I would reccomend Penninsula. In sturgeon bay, if you are into boating, there are some boat rentals right by the old draw bridge and next to the maritime museum. It is hard to say what to do to someone who hasn't been there because we go and visit our grandma up there and to a lot of fishing, and that is about it. Speaking of which, if you are a fisherman, charters are a blast, but they cost money, otherwise, the stone quarry county park is a great place for bass, and if you catch gobies, DON'T THROW THEM BACK IN, they eat other fishes eggs, they are a foreign species and all the fib's catch them, and throw them back in, you are supposed to throw them on land, and then the gulls will come and pick them up, and if you are looking for the Crew on the radio, go to WDOR out of Sturgeon Bay. If you have any questions, let me know, my Dad grew up there, and we go there a lot.