| Site of Special Scientific Interest | |
![]() Location of Cwm Cadlan. | |
| Area of search | Mid and South Glamorgan |
|---|---|
| Grid reference | SN9616809850 |
| Coordinates | 51°46′40″N 3°30′23″W / 51.777653°N 3.5064251°W |
| Interest | Biological |
| Area | 84.2 ha (208 acres) |
| Notification date | 1 January 1972 |
Cwm Cadlan is a Site of Special Scientific Interest in Glamorgan, south Wales. It is made up of a series of wet grassland fields in a small valley to the north west of Merthyr Tydfil. It is also designated as a Special Area of Conservation (SAC) and a National Nature Reserve (NNR).