Foel y Geifr is a subsidiary summit of Esgeiriau Gwynion, and included in a group of hills known as the Hirnantau. These hills rise from the south east shores of Llyn Tegid. Confusion arises when trying to establish to which mountain range these belong to. Since, Foel y Geifr forms part of the Hirnant horseshoe, many consider it to be a Berwyn peak. However, geographically it belongs to the Aran Fawddwy group, its parent peak being Esgeiriau Gwynion. It is the eastern outpost of the Arans.