The B4567 follows the left (Radnorshire) bank of the River Wye downstream from Builth Wells, parallel to the A470 on the other bank. The road was originally unclassified but gained its number in 1935.
The road starts on the A481 and heads south, initially descending steeply into the Wye Valley before running above the river. We pass through the small village of Llanfaredd then continue along the edge of the valley. The road never climbs up the steep valley side but its altitude above the river does vary, meaning that the Wye is barely visible. The long-gone Mid-Wales Railway ran along this side of the valley as well although this is now almost imperceptible.
Presently we skirt the western edge of Aberedw then cross the Afon Edw to enter a section which is wooded and more rugged. As the river bears round to the left we go with it. There used to be a tight zigzag here over the railway but this is now only visible if you know what you're looking for as the road has been improved by being moved onto the railway alignment. We pass the former Erwood station, now a craft centre, after which the B4594 comes in from the left. That road TOTSOs here, taking on the road ahead under a narrow bridge under the old railway line, and so the B4567 ends.