From Marshes, Gwent to all cities in Dyfed starting with letter Y
- Y Ferwig, Gwent
- Yerbeston, Gwent
- Ynys Tachwedd, Gwent
- Ynyslas, Gwent
- Ysbyty Cynfyn, Gwent
- Ysbyty Ystwyth, Gwent
- Yspitty, Gwent
- Ystrad Aeron, Gwent
- Ystradmeurig, Gwent
- Ystradowen, Gwent
- Ystumtuen, Gwent