Smokers are now banned from lighting up at 130 playgrounds in Gwynedd under council plans to make them smoke-free.
Signs asking people not to smoke will be erected at the council's play areas, along with leisure centres and secondary schools, from Tuesday.
The authority is the third of Wales' 22 councils to ban smoking at its play areas, following Caerphilly and Powys.
The Welsh government previously said it would work with local authorities on introducing smoke-free playgrounds.