Abyssal plains are flat, deep-sea regions found at depths of 3,000 to 6,000 meters (about 10,000 to 20,000 feet) below the ocean surface. They cover more than 50% of the Earth's ocean floor and are characterized by their smooth, sediment-covered surfaces. These plains are formed by the accumulation of sediments over millions of years, including clay, silt, and organic material. The temperature in abyssal plains is near freezing, and the pressure is extremely high, making them one of the most inhospitable environments on Earth. Despite these conditions, life exists here, including unique species like deep-sea fish and benthic organisms, which have adapted to survive in this dark and cold habitat.