Cwm Caseg

Cwm Caseg is a cwm, or cirque, located in the Carneddau range of mountains in Snowdonia, North Wales. It is a classic example of a glaciated valley landform, specifically a cwm formed by glacial erosion during past ice ages. The name "Cwm Caseg" is Welsh; "cwm" meaning a valley or bowl-shaped hollow, and "caseg" referring to a mare, suggesting the "mare's valley" or "mare's hollow."

The cwm is characterised by steep, near-vertical headwalls surrounding a relatively flat or gently sloping floor. The headwalls are formed by the plucking and abrasion action of the glacier as it moved down the mountain. The floor of Cwm Caseg may contain morainic deposits (unsorted glacial sediment) left behind by the retreating glacier, and potentially a small tarn, or glacial lake, if drainage is impeded.

Cwm Caseg is a popular location for hillwalking and mountaineering, offering challenging routes and scenic views. Its geological features make it an important site for studying glacial landforms.