Andy and Terry live in a 39-story treehouse. (It used to be 26 stories, but they added some stuff). It has the world's highest trampoline, a chocolate waterfall, a baby-dinosaur petting zoo, an active (non-erupting) volcano, a boxing elephant called The Trunkinator, the world's scariest roller coaster, and a level that is so new and so secret that Terry hasn't even finished it yet!.
General Note
"Originally published as The 39-Storey Treehouse in Australia by Pan Macmillan Australia Pty Ltd" -- colophon.