Regarded as one of the Scafells, Allen Crags is rarely climbed on its own, but rather as stepping stone towards more illustrious Wainwright fells like Great End, Scafell Pike or Esk Pike. While this is understandable considering they are very impressive fells to visit, an Allen Crags walk is rewarding in its own right and can be climbed from Seathwaite in Borrowdale. Located in Wainwright's Southern Fells, Allen Crags is more commonly reached from a ridge connecting it with the neighbouring Wainwright, Glaramara.
From the summit of Allen Crags, the best panorama of the fells is that to the north, while given its proximity, Scafell Pike looks very large indeed (and they don't come larger in the Lake District than that). Great Gable is another highlight.
Given the number of Wainwright hills closeby, it is possible to combine a number of fells with Allen Crags in one walk. The choice here is extensive, but one which is less well trodden takes in the fell alongside fellow Wainwrights Glaramara and Seathwaite Fell, sometimes known as the Grains Gill Horseshoe. Starting and finishing in Seathwaite, the 5 or so hours in between will give fantastic views into Borrowdale, across Sprinkling Tarn and a huge number of fells including good viewpoints for Yewbarrow and Great End.
Further reading on Allen Crags walks and others in the area can be found in Book Four, The Southern Fells of Alfred Wainwright's Pictorial Guide to the Lakeland Fells.