Around two-thousand athletes from 38 countries will descend on Dublin today to compete in the world-famous Ironman event.
The gruelling competition will see participants take on a 1.2-mile swim at Dun Laoghaire, a 56-mile bike through the city centre and a 13.1 mile run.
Gardaí have created an interactive map featuring live updates showing the progress of the event and the lifting of road closures - it's available online.
Mary Kate Findon from AA Roadwatch outlines some of the areas to avoid:
