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 | |
|---|---|
| Major junctions | |
| Southwest end | Aberdulais |
 A465 A4230 A4221 A465 | |
| Northeast end | Glynneath |
| Location | |
| Country | United Kingdom |
| Constituent country | Wales |
| Road network | |
The A4109 road, known as the Inter Valley Road,[1] links Aberdulais with Glynneath in Neath Port Talbot county borough, Wales.
The route begins in Aberdulais at the junction with the A4230 and A465 roads; it diverges northwards away from the A465 up the Dulais Valley and crosses through the settlements of Crynant, Ynysfforch, Seven Sisters, Onllwyn, Dyffryn Cellwen and Banwen where it has a junction with the A4221. The road then continues in a southeasterly direction along the Inter Valley Road to Glynneath where it again connects with the A465.
- ^ Highways Asset Management Plan 2023-26 npt.gov.uk page 44