(See also Elterwater Village)

Elterwater is a small, shallow lake sitting at the foot of Great Langdale 48 feet deep, 0.25 mile wide, and 0.5 miles in length. The lake is fed by water from both Great and Little Langdale, and, in turn, empties its overflow into the Brathay river.

Elterwaters name comes from the Norse word elter meaning swanwhooper swans migrate to the lake in the winter. They are only one of a large variety of wildlife that visit the reeds along the lakeshore.

There are walks in the vicinity. One leads through the larch, birch and oak woodlands nearby. Another follows the lake down to Skelwith Bridge. The village of Elterwater is north-west of the lake.