Koper, Izola, Piran and Ankaran will host the second Ironman 70.3 Slovenian Istria on 22 September.
The race will start at 9am and the last competitors are expected to cross the finish line at around 6pm.
Last year 1,400 competitors took part in the race.
This year the organisers are counting on at least 1,800 competitors, and their wish will come true as things stand now, because there are only a handful of registrations still available.
The organisers expect around 5000 visitors over the weekend.
Ironman route remains the same
After swimming off the coast of Koper, the athletes will ride through the port of Koper, Ankaran and into Italy, returning to Slovenia via Osp, Sveti Anton, Šmarje, Izola and Koper. The run will take them from Koper and via the coastal road to Izola and back to Koper.
Polish triathlete Michal Rajca wont the first Ironman in Slovenia, clocking in at 4 hours, 18 minutes and 52 seconds. The German Kristina Ziemons won the female event with a time of 4 hours, 51 minutes and 57 seconds.
The Ironman Restaurant Week, aimed at promoting Istrian cuisine, will accompany the race this year.