The B4583 is a short road on the St David's Peninsula, making it the westernmost classified road in Wales. It was originally unclassified but gained its number in 1935.
The road starts on the A487 on the northern edge of St Davids and heads north past a sports club before taking the first turn left. It heads northwest across more-or-less flat terrain, soon crossing the tiny River Alun. We continue on towards Carn Llidi (a rocky hill) and then pass a golf course to come within sight of the sea. We pass the campsite at Whitesands Bay before ending in the car park almost at sea level.