Pen y Garn
{{Short description|Mountain (611m) in Ceredigion}}
{{Use dmy dates|date=April 2022}}
{{Infobox mountain
| name = Pen y Garn
| photo = Penyfagrn.jpg
| photo_caption = The Nant Rhuddnant gorge looking north to Cefn Croes from the summit of Pen y Garn. In the background is Y Garn (left), Pen Pumlumon Fawr and Pen Pumlumon Arwystli (right)
| elevation_m = 611
| elevation_ref =
| prominence_m = 194
| parent_peak = Plynlimon
| listing = Marilyn, Hewitt, Nuttall
| language = Welsh
| location = Ceredigion, Wales
| range = Cambrian Mountains
| coordinates = {{coord|52.3785|-3.7666|type:mountain_region:GB|display=inline,title}}
| grid_ref_UK = SN798771
| topo = OS Landranger 147 or 135
}}
Pen y Garn (head of the cairn) is a mountain in the Cambrian Mountains, Mid Wales standing at 611 metres above sea level.
Pen y Garn tops a 500–600 m high plateau, which includes the controversial Cefn Croes wind farm. The summit has a very large shelter cairn hollowed out from the remains of an ancient burial cairn and a trig point. The wind turbines are very near the summit. To the north some 10 km, the whole Plynlimon range can be seen, including the summits of Y Garn, Pen Pumlumon Fawr, Pen Pumlumon Llygad-bychan and Pen Pumlumon Arwystli. 21 km to the west is the town of Aberystwyth; Drygarn Fawr lies 20 km to the SSE .Nuttall, John & Anne (1999). The Mountains of England & Wales - Volume 1: Wales (2nd edition ed.). Milnthorpe, Cumbria: Cicerone. {{ISBN|1-85284-304-7}}.