Under the stairs in a basement is often a dark, dingy place with many spiders. Since I'm likely the person who has to get things in and out of there (Brendan is too big to fit comfortably!), I really wanted to do something fun to make a space that was the least reminiscent of spider haven as possible.
So... we promised Elizabeth that we would let her paint rainbows in the basement. She decided that she'd like it to be a giant fish tank. Matthew was keen to help until he got paint on his hands, but Elizabeth would have painted the whole house given permission.