Beinn a' Chaisteil reaches a height of 886 metres (2907 feet) making it the 39th highest
Corbett and the 259th highest
Marilyn in the
UK. The mountain is well seen from the
A82 road at Auch where its western flank is seen as huge wall standing sentinel at the entrance to the Auch Glen. The
West Highland Railway travels across the base of the mountain on its western side as it loops dramatically over the Auch Glen and Glen Coralan on two viaducts. Beinn a' Chaisteil is usually climbed with the adjoining Beinn nam Fuaran to which it is joined by a
col with a height of 546 metres. Strong walkers will include the mountain in the traverse of the "Auch Corbetts", an 18 km walk with almost 2000 metres of ascent which takes in the four other Corbetts of
Beinn Odhar, Beinn Chaorach, Cam Chreag and Beinn nam Fuaran.
Etymology The mountain's name translates from the
Gaelic language as "Mountain of the Castle", a name which reflects the fortress like nature of its western flanks which fall steeply and rockily to the Auch Glen. The former spelling of Ben Achastle confirms that it is a name which goes well back into history. However the hills name may not just come from its physical appearance as W.J. Watson in his book
"Circular Forts of North Perthshire" (1913) reveals that a circular fortification stood on one of the spurs of Beinn a' Chaisteil and the name may come from that. The fort has long since been obliterated by landslips but was the most westerly of over 20 forts which existed across northern Perthshire. ==Geography==