Llyn Traffwll

Llyn Traffwll is a natural lake in the west of Anglesey (Ynys Môn), Wales. It covers roughly 91 acres, about 37 hectares, and sits midway between the villages of Rhosneigr and Valley. The A55 expressway runs less than a kilometre to the north.

What makes Llyn Traffwll special?

It ranks among the island's largest natural lakes. The other two big waters on Anglesey, Llyn Alaw and Llyn Cefni, are man-made reservoirs, so Traffwll stands apart. Together with the small lakes around it, the area is protected as a Site of Special Scientific Interest (SSSI).

What is its history?

In the 19th century the lake served as a water source for Holyhead. The Holyhead Waterworks Company drew on it from 1866, and a small dam built to manage the water level is still in place. The lake also features in Welsh literature: the novel "Madam Wen, Arwes yr Ogof" by William David Owen is set on its shore.

What else is nearby?

The RSPB Valley Wetlands reserve adjoins the lake. It lies south-east of Valley, next to RAF Valley airfield, and combines open water with reedbeds. The reserve is open all year and has an on-site car park. Regulars include tufted duck, pochard, shoveler, gadwall and grebes. In winter the water can hold hundreds of wildfowl, such as goldeneye and wigeon. In spring the reeds fill with reed and sedge warblers, and a bittern may boom. Water rail, marsh harrier and Cetti's warbler also frequent the reedbeds.

When should you go?

Birds can be seen in every season. Winter brings the largest gatherings of wildfowl and spring the liveliest reedbeds. Local sources advise arriving before 8.30 am, since jets from the neighbouring airfield get noisy later in the day. Paths can turn boggy after prolonged rain, so waterproof footwear helps. The reserve is not suitable for wheelchairs or pushchairs.

How do you get there?

The lake lies on the Rhosneigr to Valley road, close to the A55, which crosses Anglesey toward the port of Holyhead.

Frequently asked questions

Is Llyn Traffwll a natural lake? Yes. It is one of Anglesey's largest natural lakes, unlike the reservoirs of Llyn Alaw and Llyn Cefni.

Is the lake protected? Yes. It holds SSSI status together with the smaller lakes around it.

Where can you watch birds nearby? At the RSPB Valley Wetlands reserve, which borders the lake. It has a car park and a hide for birdwatching.

Why is there a dam on the lake? It was built to help control the water level when the lake supplied Holyhead.