I love bringing my daughter to Arsenal. She loves its modern art and likes to try drawing some of the pieces and installations that she sees. The venue is a mini-museum and is very spacious. This gives folks lots of room to set up for drawing, etc. It is also "mini enough" that even young kids are unlikely to get bored during a visit. I'm a fan.
[Remark: I've never been here for an event - but can imagine that this would work well given the venue's spaciousness.]