Not far from my house there is a place where people can rent a canoe to take out onto a local lake. If you have something like that available close by, that would be a good option.
Another good option would be a riverboat cruise. Search the internet to see if there is one available close by. They aren't nearly as expensive as a regular cruise. The Detroit Princess charges $20 per person for most of their cruises. If that isn't within driving distance for you, just search on google or any other good search engine.
Arboretums are great for building relationships. You can enjoy long walks and absolutely stunningly beautiful scenery while getting to know each other.
If it is someone you are serious about, a family picnic or a trip to the zoo with his family would be a great opportunity to get to know him better. You can get to know his family, and they will tell you more your love interest than he will reveal, including some of the fun embarrassing storeis =)