Natural salt pans are flat expanses of ground covered with salt and other minerals, usually shining white under the sun. A salt pan is formed where water pools evaporate. An example of a salt pan would be a lake or a pond that is located in a climate where the rate of water evaporation exceeds the rate of water precipitation, i.e., if it were not in a desert. If the water is unable to drain into the ground, it remains on the surface until it evaporates, leaving behind minerals precipitated from the salt ions dissolved in the water. Over thousands of years, the minerals (usually salts) accumulate on the surface. These minerals reflect the sun's rays and often appear as white areas.