70.4 percent is mountainous or hilly. Plains and basins make up 23.2 percent, and rivers and lakes make up the other 6.4 percent. It also occupies a large sea area. Along the coast, there are 3,061 islands each having an area of more than 500 sq m. This brings the total coastline to 6,486 km, the longest in China. Areas under cultivation total 1.613 million ha. Land used by forestry covers 6.397 million ha.