An Atlas of the Mabinogi

I gathered the 90 places named in the Mabinogion, the medieval Welsh tales that Lady Charlotte Guest translated into English, and graded each by how surely it can be found today: 31 are certain, 24 probable and 18 possible, and 17 are named in the tales and have never been found. I wanted to know whether the tales' places sit on older ground, among the tombs and standing stones of the Neolithic and the Bronze Age, so I set every place I could locate against the monuments the national records of Wales and Ireland date to those two periods.

Places and monuments

65 of the places fall within this map, drawn over 204 Neolithic and 3,233 Bronze Age monuments in Wales and 15,835 from both periods in Ireland. The Welsh record holds another 2,269 sites marked only as prehistoric, which I left off because they could belong to either period. Hover over a place or a monument, or tab to it, for what the tales and the records say about it.

Drawing the map…

The map needs JavaScript. These are the 27 certain places:

Aber Alaw, the mouth of the Afon Alaw, Anglesey: Where the seven survivors bring Branwen ashore from Ireland; here she looks back and forth between the two devastated islands, breaks her heart with grief and is buried in a four-sided grave on the riverbank.

Aber Gwy, The mouth of the Wye, Chepstow/Beachley, Monmouthshire: The second boundary marker of the final stand in the Severn, where Mabon son of Modron rode the boar down and took his razor.

Aberffraw, Aberffraw, Anglesey: The place chosen for Branwen's wedding to Matholwch, where the two hosts feast under tents because no house could ever contain Bendigeidfran.

Aberteivi, Cardigan, Ceredigion: Another stand at the mouth of the Teifi, where the boar killed Kyflas son of Kynan and Gwilenhin, king of France, who rode with Arthur's host.

Cynvael, Afon Cynfal, Gwynedd: The river by which Gronw kills the stag he has been hunting, by which he and Blodeuwedd first meet and on whose bank Lleu is struck down and, a year later, Gronw is killed in his turn.

Arberth, Narberth, Pembrokeshire: Pwyll's chief court, the seat he sets out from to hunt at Glyn Cuch and the place he returns to sit on the Gorsedd and see Rhiannon; here Pryderi is born and here Rhiannon serves her seven years' penance at the horseblock by the gate.

Ardudwy, the commote of Ardudwy, Gwynedd: The commote in which Harlech stands, named once by the text to place Bran's court precisely within the wider kingdom.

Caer Seint, Segontium Roman fort, Caernarfon: Where Bendigeidfran is conferring with his household when Branwen's tamed starling finds him and delivers her letter, its feathers ruffled to show the message bound to its wing.

Ceredigyawn, Ceredigion: The four cantrevs Pryderi adds to Dyfed and Ystrad Tywi, completing the Seven Cantrevs of Seissyllwch.

Dinas Dinllev, Dinas Dinlle hillfort, Llandwrog, Gwynedd: Where Gwydion brings up Lleu Llaw Gyffes after restoring his form, until he can manage any horse and is perfect in features, strength and stature.

Dinas Emreis, Dinas Emrys, near Beddgelert, Gwynedd: The strongest place in Lludd's kingdom, in Snowdon, where he buried the sleeping dragons in their stone chest after their mead-drunk fight in the pit at Oxford; the tale notes it was called Dinas Ffaraon before that day.

Dol Pen Maen, Dolbenmaen, Eifionydd, Gwynedd: Where Pryderi's retreating army halts a second time and sues for peace, giving hostages including Gwrgi Gwastra to secure safe passage back toward Dyfed.

Edeyrnion, Edeirnion, Dee valley near Corwen, Denbighshire: Where Caradawc son of Bran and the six other guardians are left to keep the Island of the Mighty while Bran sails for Ireland, and where Caswallawn, hidden under the Veil of Illusion, kills six of them and breaks Caradawc's heart with grief.

Hafren, The Severn estuary, between Sudbrook and the mouth of the Wye: Where Arthur summoned all Cornwall and Devon and made his final stand, forcing Twrch Trwyth into the water and prising the razor and scissors from him between Llyn Lliwan and Aber Gwy.

Hereford, Hereford, Herefordshire: The first English town Manawydan and Pryderi try after the wasting of Dyfed, where Manawydan sets up as a saddler and undersells every saddler in the town, gilding his housings in the blue enamel he learned from Llasar Llaesgywydd, until the saddlers conspire to kill them and the four move on to another town.

Glyn Cuch, Cwm Cuch, on the Carmarthenshire–Pembrokeshire boundary along the Afon Cych: Pwyll's hunting ground at the tale's opening, where he loses his own hounds to those of Arawn and strikes the bargain that sends him to Annwfn for a year; the same valley is where Arawn meets him again to close the exchange.

Harddlech, Harlech, Gwynedd: The court of Bendigeidfran where the tale opens and the thirteen ships of Matholwch are first sighted from the rock; the seven survivors return here with Bran's head and feast seven years while the birds of Rhiannon sing.

Mynyw, St Davids, Pembrokeshire: Where Arthur mustered on hearing that the boar had landed, a short ride from Porth Clais and named in the same breath as the landfall.

Penllyn, the cantref of Penllyn, around Bala and Llyn Tegid, Gwynedd: The lordship of Gronw Pebyr, out hunting the stag whose pursuit first brings him to Lleu's court, and the land he withdraws to after killing Lleu, and to which he returns once more before the final reckoning.

Porth Cleis, Porth Clais, near St Davids, Pembrokeshire: The point on the Pembrokeshire coast where Twrch Trwyth and his seven young pigs come ashore from Ireland, opening the long chase that runs the length of south Wales to the Severn.

Preseleu, Mynydd Preseli, Pembrokeshire: The upland ridge Twrch Trwyth crossed after Aber Gleddyf, and the high ground on which Arthur's hunt closed for the first pitched stand at Cwm Cerwyn.

Preseleu, Mynydd Preseli (the Preseli Hills), Pembrokeshire: Where the nobles of Dyfed meet Pwyll to press him, gently but insistently, to take a wife who can give him an heir; the meeting that sets Rhiannon's whole story in motion.

Talebolion, Talybolion, Anglesey: The commote in which Matholwch is finally paid the last of the colts owed for his mutilated horses, giving the district its name in the tale's own telling, and where the seven later land with Branwen's body at Aber Alaw.

Mur y Castell, Tomen y Mur, near Trawsfynydd, Gwynedd: Lleu's own court once Math grants him the cantref of Dinodig, on the confines of Ardudwy; the palace Blodeuwedd rules in his absence, and where Gwydion musters Gwynedd's host before marching to avenge him.

Traeth Mawr, the reclaimed estuary of the Afon Glaslyn, between Porthmadog and Penrhyndeudraeth: Where the two armies, marching in peace after the hostages are given, cannot restrain their foot soldiers from shooting at one another as they approach Melenryd.

Ystrad Tywi, the Tywi valley, Carmarthenshire: The three cantrevs Pryderi adds to his seven, part of the enlarged realm that becomes Seissyllwch.

Ystrad Yw, Ystrad Yw, around Tretower and Crickhowell, Powys: Where Llwydawg Govynnyad was finally killed after slaying the king of Brittany and two of Arthur's uncles, the last of the boar's offspring to fall.

How near

The monument records stop at the borders of Wales and Ireland, so I compared only the places they cover, which leaves out the seven in Lloegr and the two Cornish candidates for Celli Wig. Of the 48 covered places I graded certain or probable, 17 lie within 3 km of a Neolithic monument. To know whether that is a lot I needed a base rate, and I made one from 2,000 random points over Wales, keeping only those within 2 km of some recorded monument as a rough way of staying on ground archaeologists have surveyed. Of those points, 26% lie within 3 km of a Neolithic monument, against 35% of the tales' places. Random points would give a lead that size about one time in ten, which is too often for it to count as evidence.

The Bronze Age comparison tells me nothing. The Bronze Age record in Wales is so dense that 97% of my random points lie within 3 km of a Bronze Age monument, most of them because a point only got into the sample by lying near a monument already, and against that the tales' places fall well short, with 29 of the 48 (60%) that near one. Ystrad Yw in Culhwch and Olwen has the most, 27 within 3 km.

A count of nearby monuments can't tell me whether the people who told the tales knew the monuments were there. The Method sheet has the rubric I graded every place against and the full working.

Named and never found, 17 places

Aber Henvelen: The direction named for the third, forbidden door at Gwales, which looks "towards Aber Henvelen, and towards Cornwall" and which, once opened, ends the eighty years of forgetting.
Annwfn: The otherworld kingdom of Arawn, where Pwyll rules for a year in Arawn's shape, hunts, feasts and finally kills Hafgan at the Ford; Arawn's own dominions, entered and left by an exchange of form rather than by any road.
Bryn Aryen: A rise on the coast road Gwydion and Lleu take from Caer Dathyl toward Aber Menei, before they arm themselves with conjured horses at Cevn Clydno and ride on to Arianrhod's court.
Bryn Kyvergyr: The hill on the bank of the Cynfal from which Gronw, lying in ambush at Blodeuwedd's direction, throws the poisoned spear that wounds Lleu as he stands with one foot on a bath's edge and one on a buck's back.
Caer Dathyl: Math's constant seat in Arfon, where he keeps his feet in Goewin's lap between wars, where Gwydion and Gilvaethwy report back with the stolen swine and where Math punishes his nephews and afterwards conjures Blodeuwedd.
Cevn Clydno: The height above Bryn Aryen where Gwydion and Lleu equip themselves with conjured horses and change their own shapes before riding on, disguised as bards, to Arianrhod's castle.
Diwrnach House: The house of Diwrnach Wyddel, steward to Odgar son of Aedd king of Ireland, where Bedwyr seizes the cauldron by force and Llenlleog wields Caledfwlch to kill Diwrnach and his household before Arthur's men fight clear to the ship.
Hill of Tara, Co. Meath: The seat implicitly meant whenever the tale speaks of Matholwch's court: the hall Branwen is sent to as a bride, later driven from his chamber to cook for the court, where the butcher gives her a daily blow on the ear.
Irish Wilderness Cave: The cave where five pregnant women, the only survivors in Ireland of the war between Ireland and the Island of the Mighty, take refuge and bear the five sons who repeople Ireland and divide it between them.
Lli: One of two rivers, the Lli and the Archan, the text says once separated a narrower Britain from Ireland; Bendigeidfran's fleet reaches shoal water where they are said to meet, on the approach to Ireland.
Llwyn Diarwyd: The overnight halt Pwyll makes on his way from Arberth to Glyn Cuch, mentioned once and never returned to.
Llys Heveydd Hen: Rhiannon's father's court, where Pwyll travels twice: first to claim his answer and be outmanoeuvred into promising away the feast, then a year later to trap Gwawl in the enchanted bag and win Rhiannon outright.
Maenor Coed Alun: The second of the two maenors in which Math's household stands against Pryderi's men before the fighting spreads north to Nantcall.
Mochdrev: The first night's halt on the swine-drove north, in the upper part of Ceredigion, named by the text for the pigs that slept there on their way from Rhuddlan Teifi to Gwynedd.
Tŷ Haearn: The chamber of iron the Irish build to trap and burn Llasar Llaesgyfnewid, Cymidei Cymeinfoll and their monstrous children, from which only the couple escape by breaking the white-hot plates with their shoulders.
West of Ireland: Where Arthur goes, with Odgar son of Aedd king of Ireland at his side, in search of Gwrgi Seven during the gathering of dogs and huntsmen that precedes the Twrch Trwyth hunt proper.
Y Rhyd: The Ford where, a year to the night after their bargain, the man in Arawn's likeness meets Hafgan and kills him with a single blow, winning both kingdoms of Annwfn for Arawn.

Beyond the edges of the map, 8 places

Caer Lludd: London, Lloegr
Gelli Wic: Callington, Cornwall (candidate), Cornwall
Gelli Wic: Kelly Rounds (Killibury) hillfort, Egloshayle, Cornwall, Cornwall
Gwynfryn: Tower of London hill, City of London, Lloegr
Kaer Loyw: Gloucester, Gloucestershire, Lloegr
Llundain: London, Lloegr
Llyn y Peir: Loch nGualai, Devenish Island (Daim-Inis), Lower Lough Erne, Co. Fermanagh (proposed), Ireland
Rhydychen: Oxford, Oxfordshire, Lloegr

The Branches
The Four Branches and Culhwch and Olwen read as 136 deeds among 45 characters, drawn as one grid of who does what to whom and checked against 12 of the Welsh Triads.
The Gazetteer
Every place I could locate with the monuments of each class that stand within 3 km of it, the places grouped by region and the monuments by era.
The Method
The rubric I graded every place against, the two rules that sort the monuments into classes and eras and the limits of what a nearby monument can show.

The Welsh monuments are from the National Monument Record of Wales, kept by RCAHMW and published through DataMapWales under the Open Government Licence, and the Irish from the Archaeological Survey of Ireland, published by the National Monuments Service under CC-BY 4.0. The text is Lady Charlotte Guest's translation from Project Gutenberg, the coastline is Natural Earth's and the relief comes from the AWS Terrain Tiles.

An Atlas of the MabinogiAn Atlas of the Mabinogi

Places and monumentsPlaces and monuments

How nearHow near

Named and never found, 17 placesNamed and never found

Beyond the edges of the map, 8 placesBeyond the edges of the map

An Atlas of the Mabinogi

Places and monuments

How near

Named and never found, 17 places

Beyond the edges of the map, 8 places