means "Path of health". It is an initiative developed by the Irish Heart Foundation, with the aim to encourage and increase the number of people walking. It provides an easy accessible and inexpensive environment for regular exercise for walkers throughout the country.
Yellow signs on blue poles are placed at one-kilometre intervals
along each established walking route. These signs allows walkers to keep
track of how far they walk and the signs are not numbered so walkers
can start and finish at whatever point they like.
Info courtesy of Wikipedia.
Linking to signs signs