What forms the border between Myanmar and Thailand?

The border between Myanmar and Thailand is primarily defined by the Salween River, which runs along a significant portion of the boundary. In addition to the river, the border also includes mountainous regions and various valleys. The border stretches for approximately 2,401 kilometers, featuring several crossing points and areas of ethnic diversity. Various treaties and agreements have established the official boundary, though it is often influenced by historical and socio-political factors.