Hubby converted a large 5 shelf bookcase into this multi-level Guinea Pig Hutch.
Still To Add:
* female guinea pigs
* fleece bedding & pads
* etc
Pine bookcase, varnished so sealed/waterproof (non-toxic).
Design/idea based off these 3 in 'Cages > Alternative Cages':
1)
http://www.guineapig