You can lay it one of two ways – the photo below shows how that works. Up is 21″ high and Down is 15″ high at the top.
Here are some of the stats about this modern cardboard cat scratcher:
Natural Baltic Birch Wood Frame
Brown Cardboard Scratch Zone
2 1/2″ thick cardboard for years of scratching.
Overall size 13″W x 15″D x 21″H.
Scratch area is 12″ wide.