There are these lovely dedicated two way cycle lanes in Dundrum near the shopping centre... one abruptly dead-ends into a lamp post on a bend! They were incorporated into the new road design 15+ years ago, but no one has bothered to connect some of them back to other roads or cycle lanes safely. Can't blame cyclists for using the road, though unfortunately many often choose to cycle on the path beside where the cycle lane ends going round a bend in a part that barely fits two passing pedestrians... Two wrongs and all that...
If you don't know, just accept the first answer on google...