Pen yr Helgi Du

{{Short description|Mountain in Conwy County Borough, Wales}}

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

{{Infobox mountain

| name = Pen yr Helgi Du

| photo = Helgi.JPG

| photo_caption = Pen yr Helgi Du from the Craig yr Ysfa ridge

| elevation_m = 833

| elevation_ref =

| prominence_m = 85

| listing = Hewitt, Nuttall

| translation = peak of the black hunting-dog

| language = Welsh

| pronunciation = {{IPA|cy|ˈpɛn ɐr ˈhɛlɡi ˈdɨ|lang}}

| location = Conwy, Wales

| range = Snowdonia

| coordinates =

| grid_ref_UK = SH698630

| topo = OS Landranger 115

| easiest_route =

}}

{{langnf|cy|Pen yr Helgi Du|head or hill of the black hound}} is a mountain peak in the eastern part of the Carneddau in Snowdonia, North Wales.

It lies on the south-eastern flanks of Carnedd Llewelyn, and is linked to Carnedd Llewelyn over the col of Bwlch Eryl Farchog, a knife-edge ridge over the cliffs of Craig Yr Ysfa. Cwm Eigiau lies to the east and the Ffynnon Llugwy reservoir to the south. To the east of Pen yr Helgi Du is Pen Llithrig y Wrach (the slippery peak of the witch).Nuttall, John & Anne (1999). The Mountains of England & Wales - Volume 1: Wales (2nd edition ed.). Milnthorpe, Cumbria: Cicerone. {{ISBN|1-85284-304-7}}.