裂谷, or "rift valley," is a geological feature formed when tectonic plates move apart, creating a long, narrow depression in the Earth's surface. This process can lead to the formation of new landforms, such as mountains and lakes, as the land on either side of the rift sinks. One of the most famous examples of a裂谷 is the 东非裂谷, which stretches over 6,000 kilometers across several countries in East Africa. This region is known for its unique ecosystems and diverse wildlife, making it an important area for both scientific research and conservation efforts.