The Tarndale Lakes are a series of subalpine tarns and small lakes within the Molesworth area in one of the most isolated parts of Marlborough. The lakes are accessible via the Hanmer to St Arnaud road. A four wheel drive vehicle is necessary for the road between Lake Tennyson and Rainbow Station. A DOC hut and camp site are available just off the road near Lake Sedgemere.
The area is treeless and suffers from frosts many nights of the year due to altitude (approximately 1000m above sea level).
A wide variety of unique indigenous alpine plants are found in the area including a number classified as threatened.
The lakes contain the Tarndale Bully Gobiomorphus alpinus a unique species of fish found nowhere else in NZ, and some are also stocked with introduced trout, providing opportunities for fly fishing. The lakes also support a wide variety of bird life including the native paradise duck, pied stilts, pied oystercatcher and banded dotterel among others.
Four of the lakes are named, Fish Lake, Bowscale Tarn, Lake Sedgemere and Island Lake.