The main watershed runs broadly westwards from Great Gable, dividing the headwaters of Ennerdale and Wasdale.

Middle Fell begins at the unnamed col on the eastern face of Seatallan at a height of 1,525 ft (465 m).

The tarn, around 30 ft (9 m) deep, sits in a long narrow bowl, looked down on by a collection of huge boulders.

The summit area is composed of the dacitic, welded lapilli tuff of the Lincomb Tarns Formation.

Andesitic lapilli tuff occurs on either end of the ridge, together with small intrusions of basalt and dolerite.

[3] The summit cairn is sited on a small rock outcrop, close to the beginning of the ridge-end descent to the south.

A longer alternative climbs the beck to Greendale Tarn before doubling back to the summit along the Seatallan ridge.