The Kwai River is a river in western Thailand, known for its scenic beauty and historical significance. It flows through the Kanchanaburi province and is famous for the Bridge over the River Kwai, which was built during World War II. The river is a popular destination for tourists seeking to explore its lush surroundings and learn about its history. The river is approximately 390 kilometers long and is a tributary of the Mae Klong River. It is surrounded by stunning landscapes, including mountains and forests, making it a great spot for outdoor activities like hiking and rafting. The Kwai River also supports local ecosystems and communities along its banks.