To the east of Llyn Trawsfynydd lies a little-visited area of rough grassland boasting two modest tops, Foel Fawr (528 metres) and Graig Wen (550 metres). The land between them is dotted with craggy rises and small pools, with faint paths winding between them. This walk sets off alongside the lake before heading up on grassy tracks and paths to Foel Fawr. From here we can see our next top, Graig Wen, but this soon disappears from view as we make our way around the crags and pools towards it. After reaching the top, we descend steeply past the little lake of Llyn y Graig-wen, soon picking up a faint track for an easy descent to the old Braich-ddu quarries. Our return to the start takes us past the Roman site of Tomen y Mur which we will visit if time allows.