The bwlch or col between the valleys of the Senni and the Nedd Fechan at just under 490m OD is not named on the maps. The higher col (at just over 590m OD) to its immediate west is named as Bwlch y Duwynt. This translates as 'pass of the black wind' and, it has been suggested, might refer to its orientation, receiving winds from the Black Mountain direction. In this case the lower and more major col ought - I'd suggest - to be something like Bwlch y Dewynt - 'pass of the south wind'. (Would Welsh scholars excuse my possibly poor mutation.) But seriously - anyone know a name for it?