These signs have appeared on the walls of the apartments at Aalborg Place beside the towpath. It’s confusing because the towpath is signed as a cycle route and has shared-use signs at either end:
while the new signs – attached to the apartment walls – appear to have all the force of a sign such as “Do not cycle on the M6”:
They seem to be designed to cause confrontation. There appears to be nothing the City Council can do because the wall is private property, yet there seems to be no reason why we cannot continue to cycle along the towpath.
Lancaster Dynamo Cycle Campaign 
Maybe hang some signs showing the Highway Code clause explaining that rectangular signs are advisory only?
Adding that there is no footpath (footway perhaps, not sure what the towpath is classified as?) nearby would probably be OTT!
they’re NOT legal, someone with an anti-cycling bent has had these made themselves…