5 races
Event overview
This event is a true cornerstone of history. Starting in Llanberis, the heart of Eryri (Snowdonia)’s industrial heritage, this unparalleled race combines breathtaking scenery with epic challenges. 220 Tri Magazine has listed the Slateman among the world’s best triathlons, and it’s widely regarded as a bucket-list event for every triathlete — one not to be missed from any athlete’s calendar.
One of the world's best triathlons — 220 Tri Magazine
Renowned for its relentless bike course and raw scenery, this iconic event rewards grit and determination, delivering an unforgettable challenge for experienced triathletes seeking a true test.
Highlights
- Open-water swim in Llyn Padarn beneath towering Snowdonia peaks
- Clear, sheltered lake swim with stunning mountain reflections
- Legendary bike course featuring steep, sustained climbs
- Iconic ascent of Pen-y-Pass on fully closed roads
- Fast descents mixed with relentless gradients throughout the bike leg
- Challenging run through Llanberis and surrounding trails
- Continuous mountain scenery across all three disciplines
- Designed for confident, experienced triathletes seeking a serious challenge
Event photos
- All fitness levels
- Beginner-friendly
- Dogs allowed at venue
- Event village
- Free venue entry
- Spectators
- Teams
- Traders at event
Season Pass
Join the Adventure Triathlon & Duathlon Series 2026:
- The Slateman
- The Superfeet Sandman
Introducing the Adventure Triathlon & Duathlon Series 2026, a two-event journey across North Wales’ most stunning and demanding landscapes: The Slateman and The Superfeet Sandman.
By entering both events with a Season Pass, you’ll become part of an exclusive community of multi-sport athletes taking on the full adventure. You’ll also unlock extra benefits designed to make your season unforgettable:
- Guaranteed entry into both The Slateman & The Superfeet Sandman
- Free limited-edition Adventure Series hoodie
- Exclusive series results and rankings — see how you perform across both races
- Choice of distance: Sprint, Standard, or Legend (70.3) triathlon, plus Duathlon options
Whether you’re aiming for your first multi-race season or chasing podium glory, the Season Pass is your ticket to a complete North Wales triathlon experience — from the mountains to the sea.
Ready to double your adventure?
- Mountains
- Music
- Paid parking
- Rural
- Secure bag storage
- Toilets
I have been racing for 30+ years and this was not only a superb setting with outstanding scenery on the bike and run but also the toughest 70:3 run I’ve ever raced. Well organised; all the marshals and team were happy and helpful, would certainly recommend as a race to do. 2025 Participant
I entered this event based on reviews and after the fantastic time I had at the Sandman Triathlon the previous September. I cannot fault any part of the event. A stunning and demanding route on both the bike and run really pushed me, and I could have kept swimming in the lake for ages. Brilliant marshal support and organisation in Llanberis meant everything worked perfectly. I would certainly recommend this event to anyone ready for a proper challenge in beautiful surroundings. I will definitely return and hope to fit in the whole adventure series next year. Helen W
My review is long and detailed because I couldn’t find any sprint-distance-specific reviews when I was researching the race. If you are thinking about entering next year — do it, but be prepared. Claire F
A choice of four triathlon distances set in the beautiful scenery of Snowdonia. Cold open-water swim with challenging hilly run and bike courses. Meirion M
Reviews thanks to RaceCheck
Sustainability
- Bring your own cup
- Carbon offset
- Optional t-shirt
- Plastic bottle free
- Public transport links
- Recycling
- Sustainability policy
Races at event
- Sun 14 Jun 2026
- #1 of 5
09:00
Age 17 & over
£96.99-£125.99
- 750 m lake swimming
- 20.2 km road cycling + 1364 ft ascent
- 5.8 km trail running + 728 ft ascent
- Sun 14 Jun 2026
- #2 of 5
08:00
Age 18 & over
£114.99-£141.99
- 1500 m lake swimming
- 49.9 km road cycling + 2765 ft ascent
- 11.7 km trail running + 1276 ft ascent
- Sun 14 Jun 2026
- #3 of 5
07:00
Age 18 & over
£239.99-£259.99
- 1900 m lake swimming
- 92.6 km road cycling + 4297 ft ascent
- 23.1 km trail running + 2723 ft ascent
- Sun 14 Jun 2026
- #4 of 5
05:15
Age 19 & over
£419.99-£449.99
- 2.4 miles lake swimming
- 180 km road cycling + 2679 m ascent
- 44.5 km trail running + 2126 m ascent
- Sun 14 Jun 2026
- #5 of 5
08:00
Age 17 & over
£85.99-£95.99
- 5.8 km trail running + 718 ft ascent
- 49.9 km road cycling + 2765 ft ascent
- 11.7 km trail running + 1276 ft ascent