| Alyn Valley Woods and Alyn Gorge Caves | |
| Aos: | Clwyd |
| Interest: | Biological and Geology |
| Coordinates: | 53.1746°N -3.2281°W |
| Displaymap: | Wales |
| Area: | 191.1 ha |
| Notifydate: | 1 January 1957 |
Alyn Valley Woods and Alyn Gorge Caves is a Site of Special Scientific Interest[1] on the border of Flintshire and Denbighshire in north Wales. Most of the site is also designated as the Alyn Valley Woods Special Area of Conservation[2] and the southern part includes Loggerheads Country Park. The SSSI has an area of 190.3 hectares while the SAC covers 168.3 hectares.[1] [2]
A large part of the site is covered by broadleaved woodland with sessile oak, ash and sycamore among the dominant tree species.[1] Notable plants in the woods include stinking hellebore, green-flowered helleborine and wayfaring tree.[2] There are also areas of calcareous grassland with plants such as bloody cranesbill and lesser meadow-rue.[1] Much of the site lies on an escarpment of Carboniferous limestone and there are three cave systems: Ogof Hesp Alyn, Ogof Hen Ffynhonnau and Ogof Nadolig.[1] Lead ore, zinc ore, limestone and calcite were formerly mined in the area.[1]