A famous mountain dominating Llyn Ogwen and a spur of the Glyderau arc, famed as an Alpine climb. Key elements of the peak include the Milestone Buttress at the north-west base, the Heather Terrace along the east side and the slabs of the Far South Peak to the south. The summit rises to 917m above O.D. and is crowned by the striking, but natural, pair of rock monoliths known as Adam and Eve (NPRN 418785).

Tyrfan and the landscape around has been documented during Royal Commission aerial reconnaissance.

T. Driver, RCAHMW, 2009 & 2024