The B325 is a short link road in central London. The road was originally unclassified but, judging by its number, gained its status in the late 1920s.
The road starts on the southern side of Kensington Gardens, at traffic lights on the A315. Northbound B325 traffic may only turn left onto the A315 but all movements from that road are permitted. The B325 heads south along Gloucester Road, passing a number of embassies. There are a few bends on the road and a stretch lined with shops towards the central section of the route. It's not long before we reach traffic lights on the A4 Cromwell Road, where the B325 ends. Again we're not permitted to turn right.
Originally the B325 continued ahead along the remainder of Gloucester Road to end on the A3218 Old Brompton Road. This section is now unclassified meaning that the entire of the B325 is north of the A4 and therefore out-of-zone.