After nearly a year of training, athletes from around the world descend on Tenby Beach to take part in a gruelling day of Ironman competition.
Competitors face a 2.4 mile (3.8km) swim at Tenby's North Beach, a 112 mile (180km) bike ride around the national park and a 26.2 mile (42km) run. The Ironman Wales challenge was an unbelievable experience for ex-Wales rugby international Andy Moore who took part in the event this year.
"It's one of those anomalies in sport, it's just incredible," Andy said.
For more information on how to get into a multi-sport event yourself, take a look at our guide to triathlon.