Been planning a meet up and picnic with some friends at Battersea park this week but it looks like the weather is going to be crazy hot. We've got toddlers/young kids coming so I'm looking for somewhere else we could go that would be good for the kids and indoors/sheltered/air-conditioned - doesn't really matter what sort of place but ideally inexpensive, and in the Battersea/Victoria area. Any ideas? Thanks in advance :)