Snowdon, or Yr Wyddfa, is a mountain in Snowdonia, a region of North Wales. It has an elevation of 1,085 metres above sea level, which makes it both the highest mountain in Wales and the highest in the British Isles south of the Scottish Highlands. Snowdon is designated a national nature reserve for its rare flora and fauna, and is located within Snowdonia …Snowdon, or Yr Wyddfa, is a mountain in Snowdonia, a region of North Wales. It has an elevation of 1,085 metres above sea level, which makes it both the highest mountain in Wales and the highest in the British Isles south of the Scottish Highlands. Snowdon is designated a national nature reserve for its rare flora and fauna, and is located within Snowdonia National Park.