Grey Knotts is really the northern end of a ridge that runs north-east from Brandreth, but it stands separate enough to count as a fell in its own right (even if the 16m drop in height on the ridge to Brandreth isn't enough for some formal classification systems - it counts as a Nuttall but not a Marilyn).
The west, north and east slopes of the fell are almost equally steep in their upper reaches. The western slopes level out in Dubs Bottom and at Fleetwith, the eastern slopes in Gillercombe, but the northern slopes keep going down to the top of Honister Pass. The fell has a long north-eastern slope that runs down into Borrowdale and reaches Seatoller. To the south the fell merges into Brandreth.
The eastern slopes overlooking Borrowdale were the location of the plumbago mines that once provided materials for the Keswick pencil industry. These are close to Sourmilk Gill, another impressive series of cascades.
The view is impressive, with Brandreth not close enough or bulky enough to block the views, and high fells in all directions and a great view of the Buttermere area.
Grid Reference of Summit: NY 217 125
Routes of Ascent
Grey Knotts can be reached along two routes from the top of Honister Pass. The direct route follows a path that climbs steeply up the hill starting between the Youth Hostel and the quarry works and heads almost directly for the quarry.
A more gentle but longer route follows the dismantled tramway path often used as the start of an ascent of Great Gable or Haystacks. Towards the top of the climb over Fleetwith a major path turns off to the left. Follow this path south, looking out for a clear path that branches off to the left as the path runs past the rocky western slopes of Grey Knotts. Turn onto this path and follow it up the summit.
A clear path runs along the ridge from Brandreth to Grey Knotts.
Wainwright includes two routes up from Borrowdale, but I can't vouch for either of these yet.
Our ascent of Brandreth via Haystacks returns to Buttermere via Grey Knotts.
The summit area is broad and fairly level, with several rocky outcrops interspersed with several tarns.
Streams and Tarns
On its eastern flank Grey Knotts is bordered by Sourmilk Gill which flows out of Gillercomb then turns east to drop down into Borrowdale. This flows into the young River Derwent which forms the rest of the eastern boundary. A number of becks flow into the river from this flank, including Newhouse Gill.
The north-eastern boundary is formed by Hause Gill, which flows east from Honister Hause into Borrowdale.
The fell can claim a small footing at the very top of Gatesgarthdale Beck. This ends at the boundary with Fleetwith Pike, which can be placed on the nameless beck just north of the tramway.
The western boundary is less clear, but is formed by the various sources of Warnscale Beck, which join up in Dubs Bottom. The longest of these rises on the ridge between Brandreth and Grey Knotts, and forms the boundary between these two fells.
There are no named tarns, but the summit has several small tarns and there are pools on the north-eastern slopes.