The Northumbrian | Full Iron Distance
Full Iron Triathlon distance with 4 laps in the famous Kielder Water, a cycle into the Scottish Lowlands then an off-road trail run along forest trails. It's a huge challenge on the legs!
- Sun 29 Jun 2025
Full Iron Distance
06:15
Age 18 & over on 31 Dec 2025
£310-£330
- 2.4 miles lake swimming
- 112 miles road cycling
- 26.2 miles trail running
Event overview
Do you have what it takes to conquer The Northumbrian?
Kielder Forest including the largest man-made lake in Northern Europe, Kielder Water, is a vast expanse of pine forest and hard-packed trails, stretching up to the Scottish Border and is the perfect staging ground for an ultra-distance triathlon.

The ultimate endurance test will be open to a limited number of individuals and teams to conquer the beautiful waters, forests and terrain that give Northumberland and Kielder its unique character.
The summer of 2025 will welcome the fourth edition of the event which combines scenery, fortitude, adventure, and achievement. Everything it takes to be recognised as a Northumbrian.
Highlights
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Stunning location
Kielder Water is the HQ for this triathlon, providing incredible views across the water.
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Solo or team
Race individually or as a team of three to divide and conquer.
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Brutal challenge
Including steep climbs that journey into Scotland, the cycle leg is a real challenge.
There can be few greater tests of endurance and resilience and no greater sense of pride and achievement, in completing such a challenge.
This is the ultimate triathlon. The one you won't forget.
This event is part of The Northumbrian.
Event details
- All fitness levels
- Event village
- Free venue entry
- Spectators
- Swim hat provided
- Teams
- Traders at event
- Wetsuit not allowed if too hot
- Wetsuit required
- Wetsuit required if too cold
Location
- Accommodation
- Bag storage
- Bar
- Cafe
- Free parking
- Music
- Restaurant
- Rural
- Toilets
Route
- Cut off time
- Distance markers
- Entertainment
- First aid
- Food stations
- Hilly
- Marshals
- Mass start
- Multiple laps
- No headphones
- Partly closed roads
- Toilets
- Water stations
- Way markers
What's included
- Chip timing
- Goody bag
- Medal
- Physio
- Race photo
- Technical t-shirt
- Trophy
Entries
- Age 18 & over on 31 Dec 2025
- 300 places
- Entries open
- Enter online
- Event merch available
- Race pack by post
Other races at event
- Sun 29 Jun
- #2 of 2
Half Iron Distance
06:15
Age 18 & over
£195-£210
- 1.2 miles lake swimming
- 56 miles road cycling
- 13.1 miles trail running