Birthday day out suggestions please!

My son is turning 3 soon and his birthday is on a Tuesday. I'm trying to find somewhere to go for a day out for his actual birthday but pretty much everywhere I've thought of is shut on a Tuesday! I've tried Diggerland, Chessington, Ninja Warrior, Marsh Farm. Anyone got any ideas what we can do? Otherwise it will be bowling which he would enjoy but the weather looks good so ideally want to be outside. Thanks in advance!