Venus has a rocky crust, a thick basaltic rock mantle and a nickel-iron core. There is no surface water. The surface of Venus has been mapped through its cloud layer using radar. The surface of Venus is covered with roughly 20 percent lowland plains of solidified lava, 70 percent rolling uplands, and 10 percent highlands (volcanos, craters, mountains). The two major plains are called Aphrodite Terra Highlands (about half the size of Africa) and Ishtar Terra (a lava-filled basin which is bigger than the United States). At the surface, there are relatively slow winds.
Venus does not have a very strong magnetic field; this may be because of the planet’s slow rotation or perhaps Venus’ core lacks a molten outer layer.