Can anyone precisely define the Eastern and Western valleys in south Wales?

Question

Can anyone precisely define the Eastern and Western valleys in south Wales?

Answer 1

It is actually the Eastern and Western Valleys of Monmouthshire (the Glamorgan valleys go by different names.)

The Eastern Valley is based on Pontypool/Newport and the various branches thereof (Blaenavon, etc)

The Western Valley is based on Crumlin/Newport and the various branches thereof (Ebbw Vale, etc.)

The valleys to the west of the Western Valley of Monmouthshire are centered upon Cardiff; from east to west, they are the Rhymney Valley, the Merthyr Valley and the Rhondda Valley.

There are further valleys to the west which centre on Bridgend, Aberavon, Neath or Swansea