We went to the Manchester Sea Life Centre with our daughter, and she was very taken with it. I'd quote her, but she's not talking yet so you'll have to take my word for it. Rather than buy a new fish-tank, I thought she would accept a mural on the stairs for now.

This is a work in progress; I hope it to be a collaboration that she's going to want to add in some new aquatic life soon, (but not too soon, please).