This is a list of the Sites of Special Scientific Interest (SSSIs) in the Gwynedd Area of Search (AoS). [1]
Snowdonia, or Eryri, is a mountainous region and national park in North Wales. It contains all 15 mountains in Wales over 3000 feet high, including the country's highest, Snowdon, which is 1,085 metres (3,560 ft) tall. These peaks are all part of the Snowdon, Glyderau, and Carneddau ranges in the north of the region. The shorter Moelwynion and Moel Hebog ranges lie immediately to the south.
Elidir Fawr is a mountain in Snowdonia, north Wales, the northernmost peak in the Glyderau. Its name means 'Big Elidir', named after a legendary warrior king of the 6th century also known as Eliffer Gosgorddfawr.
The geology of Snowdonia National Park in North Wales is dominated by sedimentary and volcanic rocks from the Cambrian and Ordovician periods with intrusions of Ordovician and Silurian age. There are Silurian and Cenozoic sedimentary rocks on the park's margins. The succession was intensely faulted and folded during the Caledonian Orogeny. The region was uplifted as the North Atlantic Ocean opened during the Cenozoic. The current mountainous landscape arises from repeated glaciations during the Quaternary period.