First anniversary date ideas for teens?

It's my first anniversary with my boyfriend in about a week from today, and we haven't decided what we're going to do yet. We're both thinking something romantic and down-to-earth, that you can do on a small budget. I'm not really interested in something like a movie date since there's not a lot of talking/bonding involved in that, maybe something more along the lines of a picnic? At the same time a picnic seems like it wouldn't last too long and I'm sort of looking for an all-day sort of activity. Ideas?