Since then, Miyawaki and his colleagues and partners have successfully covered more than 1300 sites with multilayered protective forests, composed entirely of native species. The method has been tested successfully in almost all of Japan, sometimes on difficult substrates, including plantations to mitigate the effects of tsunamis on the coast, or typhoons in the port of Yokohama, wastelands, artificial islands, fixing crumbling slopes after road construction, and creating a forest on a cliff freshly cut with dynamite to construct the Monju Nuclear Power Plant in Fukui Prefecture.[citation needed]