A sandbar is a natural formation made of sand that rises above the water level, often found in rivers, lakes, and coastal areas. These structures are created by the accumulation of sand and sediment, which is deposited by the movement of water. Sandbars can change shape and size over time due to factors like tides, currents, and waves. Sandbars can serve as important habitats for various wildlife, including birds and fish. They often provide a safe resting place for migratory birds and can help protect shorelines from erosion. Additionally, sandbars can create shallow areas that are ideal for fishing and recreational activities like boating and swimming.