The fort consists of a fitted single sheet draped over the upper posts of the cat tower.
It wasn't long before the kitties invented a fun base jumping game.
Step 1: Go the top platform under the sheet.
Step 2: Position yourself on the outside edge.
Step 3: Drop/free fall down the side of the tower on the inside of the sheet, letting the fitted bottom catch you at the bottom. It's likely you will be pounced by another kitty when you land.
Mika: It's a fun game, I swear!