Four South Korean designers came up with a new concept for a lawn mower. The Muwi is an innovative lawn mower that calculates the size of the lawn and automatically cuts the grass., similar to how a Roomba operates. As the grass cuttings accumulate inside the machine, the Muwi constructs and compresses them into cylindrical blocks. The blocks can become balls for children to play with or discs that can be combined to make a chair. After the blocks are used, they can be left to return to nature.