Tlawng River, about 185 km long, is the longest river in the state of Mizoram. An important and useful river, it is also known as Dhaleswari or Katakha. Tlawng river passes through the Aizawl District and it flanks the eastern side of Aizawl city. Tamdil Lake on the banks of the Tlawng River is an ideal picnic spot.