At one time Eisingrug was an extremely busy area. It is located on the upper road between Harlech and Maentwrog before the lower road was built. There is a junction here, and as Eisingrug is located at the top of a very steep hill, it was an ideal place to have a mill on the banks of the Moel y Glo river. Lower down was the smithy, a wool factory and a fulling mill. There are no traces of them anymore, but the flour mill building is still there.
Over the road to the mill is Bryn y Felin, which was the home of Gwyneth Vaughan author of "O Gorlannau'r Defaid" and "Plant y Gorthrwm". There were also two chapels here - the Calvinist Methodist chapel, Peniel Chapel 1903 and Zion Chapel.