Llyn Mair (Welsh  for 'Mary's lake') is a  artificial lake near Maentwrog, in Gwynedd in North Wales (grid reference ). It lies in the area of Tan-y-Bwlch, a little above Plas Tan-y-Bwlch, and is in the catchment area of the River Dwyryd.
Llyn Mair (Welsh  for 'Mary's lake') is a  artificial lake near Maentwrog, in Gwynedd in North Wales (grid reference ). It lies in the area of Tan-y-Bwlch, a little above Plas Tan-y-Bwlch, and is in the catchment area of the River Dwyryd.