What to do for my 18th birthday?

I want to have a kick *** birthday weekend because I am finally going to be 18. I wanted to go down to Atlantic City and go to the boardwalk or the beach but I don't think that is fun enough. I want to have a blast before I go off to college in a couple of months with my two best friends. What are some good ideas for three 18 year old girls on a 3 day weekend in August? Thanks in advance.