|Location Map ( geo)|
|From:||Four Crosses, Menai Bridge (SH545727)|
|Distance:||13.9 miles (22.4 km)|
|Met (1932):||A5025, A5, B4419, B4421, B4422|
|Now part of:||A5025, A4080, B4422|
|Route outline (key)|
The B4420 was a lengthy B-road on Anglesey.
After going through Brynsiencyn there was a short multiplex with the B4419, with our road dominant, then the road went round Dwyran and entered Newborough from the southeast. It met the B4421 in the centre of the village.
Originally the B4420 ended here but it was quickly extended further. After crossing the Cefni at Malltraeth it ended on the B4422 in Bethel.
The B4420 number disappeared in 1935 with the majority becoming part of the new A4080. That road did not go into Bethel so the B4422 was extended to meet it. At the other end, the A4080 did not cross the A5 and so the section to the north became the B5420 and is now part of the A5025.