Four Mile Bridge to Trearddur Bay

Southern Ynys Gybi - an ancient secluded coast

This page outlines the coastal walk between Pont-rhydbont [Four Mile Bridge] and Bae Trearddur, part of the Anglesey Coast Path which in turn is part of the Wales Coast Path.

Note : the track is not yet shown on the map on the right yet.

Univ. of Southampton Geology Students, Ynys Gybi

Use the navigation arrows on the photograph to see other photos in this stage or LDP [note: you can also double click the image to make it full screen as well]

The photo order and description below follow the walk in a clockwise direction around Anglesey, but of course you can walk it in any direction.

This coastal stretch of Anglesey has little public road access apart from Borthwen. As someone who lived and worked in the area for several years - much of this walk was a surprise with the sandy Silver Bay and the rocky coast around Porth Saint being just two of the highlights.

Description of the stage

The walk takes in the southern section of Ynys Gybi, the island off the Isle of Anglesey. It is quite remote with little road access and so it is largely unspoiled. Anglesey contains some of the oldest known rocks on the world [see the online geology map in the references below] and this area includes a selection. There is even a memorial to a geologist [Dennis Stephenson-Wood] for his work on PreCambian geology in the area.

The horizon as constantly changing as the curve of the coast takes in most of the compass: starting south east, the Rhosneigr coast of Anglesey, clockwise to the south west, Ynysoedd Gwylanod and the Irish Sea and then north to the west coast of Ynys Gybi as far as Holyhead Mountain.

The route is not too demanding and includes a marshy section, the channel between Ynys Gybi and Anglesey, and several rocky coves as well as the two fine beaches of Silver Bay and Trearddur Bay.

There is an option south of Four Mile Bridge, for part of the year there is permissive path [recommended] through the land west of Bodior.

Note: at the southern end of Coed Tan-y-Bryn the path signage is misleading where the Bodior path rejoins the road - in that the road and permissive directions are indicated but it omits the continued route to Silver Bay.

Stage Stats

1. Places along the stage

Type Place Comment
Stage terminus Four Mile Bridge bridge. north end
Passage point Bodior permissive path
Passage point Silver Bay
Passage point Borthwen
Passage point Rhoscolyn Point geology
Passage point Porth Saint geology
Passage point Porth y garan
Stage terminus Trearddur Bay north end beach

2. Stage figures

Item Value Comment
Distance 15.2 km
Terrain type coastal moderate
Total ascent: 250 [m amsl]
Total descent: 250 [m amsl]
Lowest point 2 [m amsl]
Highest point 63 [m amsl]

3. Walk Log

Date walked Who Walking time hr Av. speed kmh Stoppage hr Direction
10 June 2016 KM&HM 3.65 4.2 1.02 clockwise

Points of Interest

Silver Bay, Ynsys Gybi Silver Bay: Once the narrow road is left behind and a field and pine wood is entered and crossed this fine sandy bay with grassy dunes and a view of the west coast of Anglesey opens up.
Borthwen, Ynys Gybi Borthwen: This is the only point with easy access and a car park. Just south of Rhoscolyn it is a large sandy bay. The path runs through banks of Dog Roses offering a scented arcade in early June.
Geology heaven, Ynys Gybi Porth Saint: The south west corner is a geologists paradise and there were 30-40 geology students on a field trip from Southampton University there the day we walked the path [2016]. The colouring of the rocks in this bay is almost a reflection of a geology map [see links below].
Bwa Gwyn (White Arch), Ynys Gybi Bwa Gwyn: Beyond Porth Saint there are two natural rock arches Gwyn [white] and Du [black]. Both are impressive.
Trearddur, Ynys Mon Bae Trearddur: has always been popular and covers a large area. On the road into the village the path passes Towyn Lodge, the building occupied by Thomas Telford in 1819-1822 while he was constructing the Anglesey section of Holyhead road [the old "A5" from London to Holyhead] which included the first bridge over the Menai Straits.

Getting there & notes to Walkers

We stayed overnight in Four Mile Bridge and had planned to walk from Rhosneigr back to Four Mile Bridge - but the local Arriva bus service let us down.

There is a regular bus service through Trearddur Bay and Four Mile Bridge and an infrequent rail service through nearby Valley

We walked a circuit ie return from Trearddur Bay to Four Mile Bridge ~ total of 19k


Start: 10 June 2016
End: 10 June 2016

References & Links:

Date Title
20160724 Ynys Gybi / Holy Island [Wikipedia
20160724 Official route map
20160724 Getting to the path on Anglesey
20160724 Geology map - zoom in to Anglesey

Updated KJM 24 July 2016