This upland is an excellent example of heather
moorland of a predominantly dry type, but with interesting
ecological transitions into a range of other upland vegetation
types, including seasonal pools containing the rare fern pillwort.
It has one of the largest red grouse populations in Wales and is
actively managed for grouse. The other upland bird populations are
also of some interest.
Managing this site
The majority of the site is common land in private ownership.
The special features of this SSSI and CCW’s views about site
management have been summarised in a Site Management Statement,
addressed to the owners and managers of the land. The statement can
be found in the resource section below.
The majority of the site is designated CROW open access land.
There are also numerous public rights of way crossing the area. For
detailed maps and information regarding access visit our access map
via the resource section below.
Much of the land lies within the parishes of Glascwm and
Gladestry, after which the two largest hills are named. Glascwm
means ‘green valley’ with glas ‘blue, green’ and cwm ‘hollow, deep
narrow valley, valley’. Gladestry may mean ‘Claud’s tree’. The
personal name (Claud or Glaud) is unrecorded; the second element is
probably Old English treow ‘tree, cross’ and frequently occurs with
a personal name to denote a meeting-place. The Welsh name is
Llanfair Llythynwg and means ‘church of Mary in Llythynwg’.