The Awarua Plain is a large area of wetland to the east of Bluff, New Zealand. Covering an area of around 600 km², the plain stretches for 35 kilometres along the coast of Foveaux Strait. This stretch of coast includes the peninsula of Tiwai Point, Awarua Bay, the Waituna Lagoon, and Toetoes Bay. The Mataura River is the major river responsible for the presence of the Awarua Plain; along with the Oreti River, it is a remnant of the rivers from the Ice Ages that formed the Southland Plains (Murihiku). In addition, several small streams enter Foveaux Strait along this stretch of coast, mainly via Awarua Bay and Waituna Lagoon.