Glas Bheinn is a Graham of 635.3 m in Highland. Its drop clears the 150 m Marilyn standard by only 1.4 m.
Only three Grahams have less drop. All four of its nearest neighbours are higher, up to Sgurr Ghiubhsachain at 849.2 m. All four of its nearest neighbours lie to the west, so it stands at the eastern edge of its group. It is the lowest of the 17 register hills in the Sunart and Ardgour region, where Sgurr Dhomhnuill is highest. It is 230.4 m below the average height of the 427 register hills in Highland. The summit is marked by a trig point.