| Site of Special Scientific Interest | |
| Location | Carmarthen |
|---|---|
| Grid reference | SN4812023870 |
| Coordinates | 51°53′33″N4°12′31″W / 51.89263°N 4.2085591°W |
| Interest | Biological |
| Area | 1.65 ha |
| Notification | 12 June 1984 |
Cae Cwm-tywyll is an unimproved hay meadow that is a Site of Special Scientific Interest in Carmarthenshire, Wales.