Lôn Las Cefni is a delightful cycleway which links Newborough Forest on the south coast of Anglesey to Llyn Cefni. The route arcs around the landward margin of the Malltraeth estuary and then follows the banks of Afon Cefni inland across the Malltraeth Marsh (look out for birds here) before continuing into the market town of Llangefni. There is a 2km section of lane on this stretch but the road is very quiet and straight so you are unlikely to be surprised by any speeding cars. If you have time while in Llangefni do pay a visit to the Anglesey Museum (Oriel Ynys Mon).
The final section continues to follow Afon Cefni; this time though you pass through a delightful wooded area known as the Dingle and along a meandering valley. The valley opens out at Llyn Cefni where a choice of finishes awaits. The left hand route ends after 1km at the western end of the lake, while the right hand route takes you to a car park just off the B5111 at the northern end of the lake.
The route is mostly quite flat, although there are some inclined sections near the start and a short steep ascent at Llyn Cefni.
Start from the forest car park at the northern tip of Newborough Forest, just off the A4080.