Clipyn Du

{{Short description|Hill in Powys, Wales}}

{{refimprove|date=February 2024}}

{{Use dmy dates|date=April 2022}}

{{Use British English|date=February 2024}}

{{Infobox mountain

| name = Clipyn Du

| photo =

| photo_caption =

| elevation_m = 582

| elevation_ref =

| prominence_m = 124

| prominence_ref={{cite web |title=Clipyn Du [Tarren Bwlch-gwyn] [Siambr Trawsfynydd] |url=https://www.hill-bagging.co.uk/mountaindetails.php?qu=S&rf=3444 |website=Hill Bagging |publisher=Database of British and Irish Hills |access-date=4 February 2024}}

| coordinates = {{coord|52|31|22|N|3|46|14|W|type:mountain_region:GB_scale:100000|format=dms|display=inline,title}}

| range_coordinates =

| listing = HuMP

| range = Cambrian Mountains

| parent = Pumlumon

| location = Montgomeryshire

}}

Clipyn Du is a mountain in northern Powys in Wales. Also known as Tarren Bwlch-Gwyn or Siambwr Trawsfynydd, it is one of the higher summits of the area and is located a few miles north of Plynlimon (Pumlumon). It has an elevation of {{cvt|582|m}} and a topographic prominence of {{cvt|124|m}}, so is classed as a HuMP, having over 100 metres of prominence. Tarren Bwlch-Gwyn is the name of a steep-sided escarpment nearby. Nearby is a lake, Glaslyn.