Middle Fell begins at the unnamed col on the eastern face of Seatallan at a height of 1,525 ft. This is its only connection with other high ground, being constrained on three sides by deep valleys. To the west, separating Middle Fell from its parent, is Greendale Gill. This begins at Greendale Tarn, nestled into the steep face of Middle Fell. The tarn, around 30 ft deep, sits in a long narrow bowl, looked down on by a collection of huge boulders.