|Location Map ( geo)|
|Distance:||23.8 miles (38.3 km)|
|Meets:||A5025, B5112, B4422, A5114, B5111, B5420, A5025, A545, unclassified|
|Route outline (key)|
The B5109 is a long B-road on Anglesey.
It starts on the A5025 in Llanynghenedl, close to the west coast of the island and heads east. It is crossed by the B5112 at Trefor before passing to the south of the Cefni Reservoir near Bodffordd. It then reaches Llangefni.
After going over a disused railway line the B5109 gets lost in the town's one-way system. Westbound traffic can just head straight but eastbound traffic has to go round the other three sides of the rectangle, which appears to follow the B5111.
The B5109 heads northeast out of Llangefni to Pentraeth, where it crosses the A5025 again, before heading more southerly to the east coast at Beaumaris, descending steeply into town. It meets the A545 at a T-junction on Castle Street. There is a short multiplex west along Castle Street before the B5109 turns left along Alma Street and heads east once more, parallel to the A545. At a T-junction by the castle the road TOTSOs right, with the road to the left being the A545 (the shorter route for traffic heading in our direction).
The road then heads north along the coast, getting very close to the sea for a distance, before heading more inland, although still in a northerly direction. It reaches Llangoed and runs along the main street before ending at the road junction by the village car park, just before a bridge over a stream. The other roads here are unclassified.
Originally the B5109 only went from the B5111 in Llangefni to the A525 in Beaumaris but was soon extended east to Llangoed. In 1935 it was extended west to Llanynghenedl, taking over that part of the B5112 west of Trefor in the process.