I guess the faeries kept its entrance hidden from you Caberfeidh ..here is an extract from "Glen Lyon: the valley of the Sun God" by Phillip Coppens web page. The area is full of magic and mystery..its the epi centre of powerful lay lines
Mount Schiehallion
In modern times, the fame of the Glen has been eclipsed by another fairytale: Mount Schiehallion has been described as the hill of the Daoine Shi, the “Fairy Hill of the Caledonians”, betraying a history with the “fairy people”. The area is therefore one where legend has it that people have been whisked away to the “Otherworld”.
Of particular connection with fairy mountains are their symbolism as entrances into the Otherworld, normally negotiated by caves. There are two main groups of caves on the north side of the mountain: Foss caves near the Braes of Foss car park, and Lassintullich caves, about 2 km northwest of the summit. A third group is in Gleann Mor, on the south side of the hill, beside shielings on the left bank of the Allt Mor. The Ordnance Survey map names one of the group, the Uamh Tom a’Mhor-fir (cave of the great man of the bushes).
It is the best known of approximately 26 caves that have been discovered in the limestone, many are no more than tiny potholes, but some are more than 40 metres long. It is this cave that has been identified as the entrance to the Otherworld. Uamh Tom a’Mhor-fir is known as the cave where fairies loved to dwell. Folklore has it that “there, it is said mortals from time to time dwelt among them, and interesting stories are told of the strange ways in which they were rescued from their power.
I have visited the Praying hands and the House of the Cailleach..but never found the entrance to the Otherworld. I guess its not my time yet ..nor yours