princes of gwynedd

Driving Tours

Route 3 - Anglesey

Penmon Priory

Penmon Priory

St Seiriol's Church

St Seiriol's Church

Beaumaris Castle

Beaumaris Castle

Beaumaris Church - Joan’s coffin

Beaumaris Church - Joan’s coffin

Aberffraw – St Beuno’s Church

Aberffraw – St Beuno’s Church

This route takes you onto Anglesey to explore Penmon Priory, Llanfaes where Joanna was exiled for a time, onto Beaumaris where Joanna's coffin resides in the church and finally Llys Rhosyr and Aberffraw, both Royal Courts for many centuries.

  • Penmon
    • Penmon Priory
    • St Seiriol's Church & Well
  • Aberlleiniog
  • Llanfaes
  • Beaumaris
    • Beaumaris Castle
    • Church of St Mary and St Nicholas
  • Newborough - Llys Rhosyr
  • Aberffraw
  • Llangadwaladr

Start Point: Betws-y-Coed. LL24 0BN

Along the way:

The A5 will take you along the Ogwen Valley. The Ogwen Valley is the most northerly of the main valleys in the Snowdonia National Park. The mountains that surround the valley are about 1,000 metres high and the terrain varies quite considerably with cliffs that reach about 300-400m in height and are very popular with climbers. There is also open moorland with heather, bracken and sheep, as well as areas of dense forest around Capel Curig

There are two bridges joining the mainland and the Isle of Anglesey across the Menai Strait; the Menai Bridge and the Britannia Bridge. A ferry used to be the only way of crossing the Menai Strait and when Ireland joined Britain by the Act of Union in 1800, Thomas Telford was given the task of improving the link from London to Holyhead and as part of that task, he built the Menai Bridge which was completed in 1824. The Menai Bridge is a suspension bridge but is unusual because it was required to have 100 feet clearance beneath it to allow sailing ships through. The Britannia Bridge was originally designed to take the railway and was designed by Robert Stephenson, opening in 1850 but it was redesigned in the 1970s to carry a road on top of the railway.


“… forces had been landed in Anglesey and during the first fortnight of September, the crops so essential to support the Welsh of the mainland during the winter were harvested by the English” [From: The Oxford History of England, The Thirteenth Century]

Anglesey could be called the bread basket for North Wales in medieval times as the farmland provided the crops to feed the people of North Wales over the winter months.


“The priory, according to some historians, was originally founded in the sixth century, by Maelgwyn Gwynedd, and subsequently enlarged by Grufydd ab Cynan, who appointed his son Idwal prior, in 1140. Llewelyn ab Iorwerth, in 1220, made considerable additions to its revenue, and placed in it monks of the Benedictine order, in whose possession it remained till the Dissolution …” [From: Lewis's Topographical Dictionary of Wales (1849).

Penmon Priory and the neighbouring church were founded by St Seiriol who was a hermit in the 6th Century and the foundations of his cell are by the well at the rear of the church. The present church dates from 1140 when it was rebuilt by Owain Gwynedd and the nave is from that period. Due to Llewelyn Fawr's influence, it became an Augustinian priory in the 13th Century when Llewelyn Fawr greatly increased the priory's revenues – he granted a charter to the Priory of Penmon in 1221. Llewelyn Fawr granted a further charter to Penmon in 1237 giving rights over land including the lands of Lleiniog (see Castell Aberlleiniog below). It is believed that a section of the church wall could be as old as 6th Century which would make it the oldest Christian building in Wales. There are two ancient crosses circa 9th/10th Century within the nave of the church which probably stood by the gates in the monastic enclosure.

Moving on: From the car park, turn left at the car park entrance and walk along the road verge for about 150 metres. The footpath entrance (discernable by timber bollards, a kissing gate and a field gate) is on the right after the bridge.

If you have time, explore:

  • Castell Aberlleiniog
    This little known castle was built around 1088 by Hugh of Avraches, Earl of Chester, after his victory over Gruffydd ap Cynan, King of Gwynedd, who was the great-grandfather of Llewelyn Fawr. When Gruffydd escaped imprisonment at Chester and raised an army in 1094, the castle was captured and burnt to the ground. A motte and bailey castle with a moat were built at Lleiniog during the 1630s by Thomas Cheadle.

    The Royal Commission on Ancient and Historical Monuments in Wales describe it as “a mediaeval stone structure, much ruined, about 60 ft square, with a circular tower on three of its corners, that to the N. restored. A fourth undoubtedly existed but no traces now remain. Each had 5 rectangular loops with splayed reveals. On the NW side is a projecting garde-robe formed by rough corbels supporting a stone slab. Each wall has 3 buttresses which are additions, but the position of the garde-robe suggests that they replace earlier ones. The structure is probably late mediaeval ....”.

    500 metres to the east, there is the site of another castle mound which is believed to be the outworks of the main castle (on the north side of the car park).
  • Llanfaes - LL58 8LG
    “Joanna had been buried on a raw day in February. Llewelyn had been just a boy, only eight, but more than four decades later the memory was still vivid, sharply etched; he had only to close his eyes to see his grandfather standing alone by Joanna's marble tomb. Now it was his turn to bury a wife at Llanfaes … Each time he looked up, saw the soft June sunlight spilling through the windows, he felt a dulled sense of surprise, expecting to see the panes streaked by a frigid February rain.” - from 'The Reckoning'
    Llanfaes was the major port and greatest market of Gwynedd, the trading links raising taxes to pay for the wars against the English. Joanna was banished to Llanfaes after her allegedly adulterous affair with William de Braose. In 1237 Llewelyn Fawr endowed a Franciscan Friary to receive the body of his wife, who had died at Aber. Subsequently, other Gwynedd female royalty were interred here including Senena and Eleanor de Montfort, respectively the mother and wife of Llewelyn the Last. The site of the Friary is not accessible and in any event little remains of the Friary; Joanna's coffin is now at Beaumaris Church. Upon the building of Beaumaris Castle, the village of Llanfaes was depopulated and the people moved to the new borough of Newborough, which you will visit later on in this tour.

Moving on

Along the way: Ethnic cleansing is not a new concept. When Edward I reached Llanfaes, he forced all the Welsh people to move to a new village called Newborough. However, the worst effects were felt in the towns of Conwy, Caernarfon and Beaumaris. No Welsh people were permitted in the towns and they were mostly inhabited by the English with a few people from Ireland, Gascony and Savoy. 1,500 hectares around those towns was also cleared of Welsh people in order that the colonists had fields for crops and livestock. The villages of Aberystwyth and Lleweni were similarly cleared of Welsh people.


“[Edward I]determined to erect a castle, equal in strength and importance to those which he had previously founded at Carnarvon and Aberconway, and to place in it a formidable garrison, to counteract the efforts of the unsubdued spirit of the Welsh” [From: Lewis's Topographical Dictionary of Wales (1849)]

Llewelyn the Last, and after him Madoc (believed to be a distant cousin), made Anglesey the theatre of several insurrections and Edward I erected a castle to counteract the efforts of the unsubdued spirit of the Welsh. Beaumaris Castle was built for Edward I and was completed in 1296. There is an exhibition detailing the castle's history including about the occupation by Owain Glyndwr. The Church of St Mary and St Nicholas has some notable treasures including choir stalls which are believed to be from Llanfaes Priory and the stone coffin and lid of Joanna/Siwan. Regrettably the location of her remains is not known. Curiously, Llewelyn Fawr's body also disappeared after his coffin was moved following the dissolution of Aberconwy Abbey.

Moving on. On arriving in Newborough, it's probably easiest to park near the Prichard Jones Institute. You can walk up to Llys Rhosyr from there after you've seen the show and display.


“…she walked in the meadows near Rhosyr, taking care not to venture into the marshlands that lay off to the west, where the River Cefni wound its way to the sea.” - from 'Here Be Dragons'

Llys Rhosyr was a Royal Court which Llewelyn Fawr developed into a palace and a charter of Llewelyn Fawr was issued here in 1237. It was from halls such as Rhosyr that Gwynedd was governed. When the king was in attendance at the llys he might summon his councillors and other important men from the commote to meet him; business would be done in the hall during the day and in the evening, feasting and entertainment would take place around the great open hearth. The work at Rhosyr stopped when Llewelyn the Last was killed in 1282 – Gwynedd Archaeological Trust has excavated the site.

Before going to Llys Rhosyr, visit the Prichard Jones Institute to see their audio-visual show and display as an introduction to life in the Royal Court (please check opening times before going as it doesn't open every day) and afterwards walk over to the archeological site of Llys Rhosyr.

For more information about Llys Rhosyr, visit:

Moving on


“This place, which derives its name from its situation at the mouth of the small river Fraw, was distinguished at a very early period as the principal residence of the ancient princes of North Wales, … having removed the seat of government to Caer Seiont, now Carnarvon, it was re-established at Aberfraw, in the year 870, by Roderic the Great…. Roderic fixed his supreme court of judicature at this place, which, until the death of Llewelyn, in 1282, continued to be the ordinary residence of the Welsh sovereigns.” [From: Lewis's Topographical Dictionary of Wales (1849)]

Aberffraw was the principal residence of the ancient princes of North Wales, by one of whom, Caswallon Law Hîr, a palace was built, about the middle of the fifth century. Llewelyn Fawr took the title Prince of Aberffraw and Lord of Eryri as a symbolic gesture. Today there is a superb 12th century Romanesque chancel arch in St Beuno's church, a remnant of the royal chapel of the Llys (for entry to the church, ask at the Post Office in the centre of the village). The Llys (the royal court) is believed to be beneath the present village centre.

If you have time, explore:

  • Llangadwaladr – The Church of St. Cadwaladr is believed to have been a royal chapel and burial ground for the court at Aberffraw in the 6th Century. A window dates from the 12th Century. SY10 7QP

If you have time, explore these but they are a little out of the way:

  • Hen Capel Lligwy – This remote roofless chapel shows signs of construction between the 12th and 14th centuries and was probably the site of the Llys at Penrhosllugwy. LL72 8NH
  • Cemaes/Llanbadrig Church – The most northerly village in Wales was once a busy port. The church (part 12th century) was originally the royal chapel associated with the Llys of Cemaes. LL67 0LN

To complete the route, please return to the start point in Betws-y-Coed. LL24 0BN

Along the way: The village of Bethesda grew up due to the slate and stone quarries in the area. The slate has a reputation for being high quality and is a dark blue-green colour. The largest slate quarry is Penrhyn Quarry, first developed in 1770. Penrhyn Quarry, a huge pit a mile long and 1200 ft deep, is reputedly the world's largest slate quarry. Profits from the quarry financed the construction of Penrhyn Castle at nearby Bangor. A feature of the castle is the great four-poster bed of Penrhyn slate, which weighs four tons

The location of the main points of interest are shown below. Use the 'Satellite' button to get an overhead photo of the locations (best if zoomed in first).

A - Betws-y-Coed
B - Penmon
C - Castell Aberlleiniog
D - Llanfaes
E - Beaumaris Castle
F - Church of St Mary and St Nicholas
G - Pritchard Jones Institute, Newborough
H - Llys Rhosyr
I - Aberffraw
J - Llangadwaladr
K - Hen Capel Lligwy
L - Cemaes/Llanbadrig Church

Get Directions from Googlemap

Get route directions from Googlemap

List of all Driving Tours

Route 1 - Betws-y-Coed to Abergwyngregyn

Visit possibly the finest medieval fortifications in Britain at Conwy Castle and the home village of the Princes of Gwynedd at Abergwyngregyn.
Find out more

Route 2 - Betws-y-Coed, Llanrwst and Trefriw

A short route but perhaps the most evocative as you walk in Llewelyn Fawr’s footsteps.
Find out more

Route 3 - Anglesey

Visit the bread basket of North Wales with its atmospheric churches and the World Heritage site at Beaumaris Castle. (You are on this page).

Route 4 - Bangor, Caernarfon and Llanberis

From natural history at Swallow Falls to man-made history at Caernarfon Castle and Bangor Cathedral.
Find out more

Route 5 - Beddgelert, Criccieth and Dolwyddelan

Castles galore, including reputedly Llewelyn Fawr’s favourite at Dolwyddelan.
Find out more

Route 6 - North-East Wales

Let history speak to you as you explore the grim past of Rhuddlan castle.
Find out more

Contact Information

For more information please contact us at:

E-mail: info at princesofgwynedd dot com

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