|To:||Princes Gate (SN134127)|
|Length:||1.6 miles (2.6 km)|
|Old route now:||A4115|
|Route outline (key)|
The B4315 is a short link road in southern Pembrokeshire.
Today it is at Templeton, on the A478, that the B4315 begins its run towards Princes Gate, southeast of Narberth. Formerly, however, the route began some 4 km further west at Cross Hands, on the A4075.
The original eastern end of the B4315 was in Templeton. By the early 1930s it had been extended east along the former A4072 to meet the newly rerouted B4314 at Princes Gate, lengthening the road to its fullest extent.