My corns currently live in this:
Of course, I've since taken the divider out of the top cage to make it one cage but otherwise it's the same as when I made it, and works like a charm for corns.Before that, they lived in tanks and tubs and were not as happy.
FYI, this system is four 36x18x14 cages, single piece sides (so all one unit), made of plywood with plexi doors and tile floors.