The Moelwynion (a Welsh plural, sometimes anglicised to Moelwyns) are a group of mountains in central Snowdonia. They extend from the north-east of Porthmadog to Moel Siabod, the highest of the group. The name derives from the names of the two largest mountains in the group, Moelwyn Mawr (great white hill) and Moelwyn Bach (little white hill).
Summit of Moel Siabod (872m) via its East Ridge (1). As part of summer QMD on 20/09/12 - see walking logbook. 
