Yr Eifl, sometimes called the Rivals in English,[1][2][3] is a group of hills on the north coast of the Llŷn Peninsula in Gwynedd, Wales.

On a clear day, the views from the highest summit reach as far as the Isle of Man, the Wicklow Mountains in Ireland and the Lake District, as well as the entire sweep of Cardigan Bay.

The view of Yr Eifl is especially prominent from the SW coast of Anglesey, for instance from Ynys Llanddwyn.

[5][6] It has a microwave radio relay station on it, as well as cairns and granite quarries (which produced the material for the curling event at the 2006 Winter Olympics), and a cliff face dropping to the Irish Sea at Trwyn y Gorlech.

Routes lead onto the hill from the nearby villages of Llithfaen to the south, Llanaelhaearn to the east and Trefor to the north.