The Clain River is a small river located in western France, primarily flowing through the Vienne department. It is approximately 90 kilometers long and is a tributary of the Vienne River, which eventually joins the Loire River. The Clain River is known for its scenic landscapes and is popular for recreational activities such as fishing and kayaking. The river passes through several towns, including Poitiers, where it contributes to the local ecosystem and provides water for agriculture. The Clain River also plays a role in the region's history, as it has been a natural boundary and resource for communities along its banks.