The B9133 is a short road serving the harbour area in Montrose. Unsigned, and hardly ever marked on maps, it is a remnant of a time when much of Scotland's trade was by sea. However, despite this, the road was not classified in 1922; owing to its short length its history is not fully known but it had received its number by 1950, and probably twenty years before.
The route starts on the A92 at the roundabout at the north end of Montrose Bridge and heads east along Wharf Street, running parallel to the old wharf along the River South Esk. It then bears left into Hill Street and turns right into River Street, before TOTSOing left into Commerce Street a short distance later. The route then ends at the crossroads with Ferry Street, where left and straight ahead are unclassified roads. Curiously, however, Ferry Street to the right is the B9100, the last remnant of a route that once ran from the town centre down to the harbour. The route has occasionally been labelled as the B9113 in the past, but this is an error.