The 26-Storey Treehouse (Paperback) by Andy Griffiths and Illustrated by Terry Denton.
Join Andy and Terry in their newly expanded treehouse, which now features 13 brand-new storeys, including a dodgem car rink, a skate ramp, a mud-fighting arena, an anti-gravity chamber, an ice-cream parlour with 78 flavours run by an ice-cream serving robot called Edward Scooperhands and the Maze of Doom – a maze so complicated that nobody who has gone in has ever come out again... well, not yet, anyway.
Well, what are you waiting for? Come on up! (352 pages).