|Length:||6.8 miles (10.9 km)|
|Meets:||A44, B4372, B4356, B4355|
|Route outline (key)|
The B4357 is a short rural B-road in eastern Radnorshire.
It starts on the A44 at Walton and heads northwards. After going through Evenjobb it climbs to Beggar's Bush where the B4372 leaves to the left. It then descends steeply to Bridge End where it crosses a narrow bridge over the River Lugg. Shortly afterwards it goes through Whitton where it crosses the B4356; that road has priority.
The B4357 then climbs out of the valley to Rhos-y-Meirch where it ends at a T-junction on the B4355. Knighton is just a short distance to the left.