What are some fun things to do in a large group?

I just finished running my high school's annual musical with a very big cast, and we are all extremely close friends and love doing things together. Even so, because there was such a big cast, it's hard for us to do things because only a few people have houses big enough to fit all of us. Sometimes we go bowling and hang out outside, but few people also have big enough yards. I would invite everyone over myself, but I had a party recently with about fifteen kids and the house was too small, let alone about 40. I know going to a mall or a movie would be nice, but it would be a group of literally about 40 kids crowding up the place. We'd be walking from store to store in a giant, unreasonably large group.

What are some fun ideas for large groups? Where can we all go? I know there have to be some fun ideas for big groups of teenagers! Haha, thank you in advance for your help.

:)