Ideas for teen party in London

[EE123]

We are moving out of London and my 15 year old daughter is interested in having a leaving party, but of course everything I suggest is wrong. She wants to have a water gun fight in a park, but that sounds like a disaster waiting to happen. Any suggestions and ideas in central or west London would be greatly appreciated. Approximately 30 kids.

[cdtaylornats]

Paintball?

[EE123]

Ill look in to it, now she is saying she wants a dance party, and Im trying to figure out where I can do that inexpensively.