Wookey Hole Caves then passes through major cave systems such as Swildon's Hole, Eastwater Cavern and St Cuthbert's Swallet, around Priddy, but 95% is water that has percolated directly into the limestone. The southern slopes of the Mendip Hills largely follow the flanks of an anticline, a fold in the rock that is convex upwards and has its oldest beds at its core. On the Mendips the crest of the anticline is truncated by erosion, forming a plateau. The rock strata here dip 10–15 degrees to the southwest. The outer slopes are mainly of Carboniferous Limestone, with Devonian age Old Red Sandstone exposed
Alyn Valley Woods and Alyn Gorge Caves Alyn Valley Woods and Alyn Gorge Caves Alyn Valley Woods and Alyn Gorge Caves is a Site of Special Scientific Interest 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 and the southern part includes Loggerheads Country Park. The SSSI has an area of 190.3 hectares while the SAC covers 168.3 hectares. A large part of the site is covered by broadleaved woodland with sessile oak, ash and sycamore among the dominant tree species. Notable plants in the woods include stinking hellebore, green-flowered