The Ground Tunnel is great way to allow your cat to be able to run through your garden if you have some Ground runner connected to your Cat Enclosure. Your cat can enjoy the grass or earth between it's claws. They are also a great way to connect 2 or more Cat Enclosures together for even more room for you feline to enjoy the great outdoors. They are also use to link the Enclosure up to you house with a cat flap in the window or wall.