Aghla Beg is a Marilyn of 602.3 m in Donegal. All four of its nearest neighbours are higher, up to Errigal at 747 m.
Only one of the 104 hills profiled in Ireland is lower. It is the lowest of the five register hills in the Derryveagh, Glendowan region, where Errigal is highest. On the Marilyns height ladder it sits between Beinn a' Chuirn (602.6 m) and Sgorach Mor (602.2 m).