The Glyderau are a mountain group in Snowdonia, North Wales. The name derives from the highest peaks in the range, Glyder Fawr and Glyder Fach. According to Sir Ifor Williams, the word "Glyder" derives from the Welsh word "Cludair", meaning a heap of stones. The Glyderau stretch from Mynydd Llandegai to Capel Curig, and include five of Wales's fourteen or fifteen summits over 3000 feet; these include Tryfan, considered one of the finest mountains in Wales and one of the few mountains on the British mainland requiring scrambling to reach the summit. The eastern half of the range in particular, including Glyder Fawr, Glyder Fach and Tryfan, is very popular with walkers and climbers.
Dinorwig Power Station, a hydroelectric pump-storage system, is located in a man-made cavern within Elidir Fawr. The slopes of the Glyderau also include the lake Llyn Idwal, and a number of classic climbing areas such as the Idwal Slabs.