Segura Extreme Triathlon

Embalse del Tranco / Segura de la Sierra, Spain · May · Independent (listed with global extreme triathlon calendar)

Why people love it

Night swim of about 3.6 km (2.2 mi) in the Tranco reservoir
Finish at the Segura de la Sierra castle
Three first-category climbs including El Yelmo, 4,000 m (13,100 ft) of total climbing
Natural park setting

Wetsuit mandatory; gloves and booties banned
Swim may be shortened or cancelled and the race turned into a duathlon
Sources disagree on distances: swim 3.5-3.8 km (2.2-2.4 mi), bike 175-180 km (109-112 mi)
No athlete race reports found
Date drifts between May and June

2.5Good

How racers feel about it, how well it is run, and how it treats a first timer. Counts for 27% of the overall score.

Racer satisfactionLoved3.6
Only local press, with no participant quotes, calls it one of Spain's most demanding races in a striking park setting. · Low confidence
OrganizationAdequate3.2
No athlete feedback; seven editions suggest stability, but the field is small and the swim can be cut, turning it into a duathlon. · Low confidence
First timer friendlyExperts only1.1
The organiser says only well-trained athletes should enter: a night swim, 4,000 m (13,100 ft) of bike climbing and a trail run. · High confidence

PR potentialVery slow1.1
4,000 m (13,100 ft) of bike climbing plus 1,900 m (6,200 ft) on the trail run makes it one of the slowest courses. · Medium confidence
Course easeExtreme1.1
A night swim, a 180 km (112 mi) bike with 4,000 m (13,100 ft) of climbing, then a trail run with 1,900 m (6,200 ft). · High confidence

3.7Very good

Wetsuit odds, water temperature, calm, and the experience of the start. Counts for 15% of the overall score.

Wetsuit legalAlmost always4.8
A wetsuit is mandatory, with stated water of 18-22 °C (64-72 °F); the swim could be cancelled into a duathlon. · Medium confidence
Water temperatureAcceptable3.2
The organiser forecasts 18-22 °C (64-72 °F), but a pre-dawn mountain reservoir in May is likely nearer 15-18 °C (59-64 °F). · Low confidence
Calm waterMostly calm4.4
A sheltered reservoir with no current, though a 3.6 km (2.2 mi) deep-water swim in a mountain valley can pick up wind chop. · Low confidence
Swim easeHard2.3
A night start from the water after a boat transfer, with a mandatory buoy with chemical light; 3.6 km (2.2 mi) with hard navigation. · Low confidence
Swim experienceFine3.4
An atmospheric night swim with boat support, but no clarity data and no scenery until dawn. · Low confidence

3.3Good

Road surface, closures, scenery and wind. Counts for 19% of the overall score.

Road surfaceMixed3.0
No data; probably average rural mountain roads. · Low confidence
Road closuresPartly closed2.7
Rural roads with minimal traffic, but closure level is not documented. · Low confidence
Bike scenerySpectacular4.5
Cazorla, Segura y Las Villas natural park, described as striking by the press. · Low confidence
WindSome wind3.2
No wind data; exposed passes in the Sierra de Segura can be gusty. · Low confidence

Bike speedVery slow1.1
4,000 m (13,100 ft) of climbing over 175-180 km (109-112 mi), with three first-category climbs. · Medium confidence
Bike flatnessMountainous1.0
About 4,000 m (13,100 ft) of gain, among the hilliest of any full. · High confidence
Bike simplicityTechnical2.0
Steep ramps and long descents off the named passes (El Yelmo, La Cumbre, Despiernacaballos). · Low confidence

2.7Good

Crowds, aid stations, conditions underfoot and scenery. Counts for 13% of the overall score.

Crowd supportSparse1.8
A remote loop with a small field; support is concentrated at the castle finish. · Low confidence
Aid stationsStandard3.0
No data; the race manual was not available. · Low confidence
Run scenerySpectacular4.6
Forest and mountain trail finishing at the castle of Segura de la Sierra. · Low confidence
Run conditionsBrutal1.2
43 km (27 mi) of forest track and trail on GR 247 after a 180 km (112 mi) mountain bike; hard footing and fatigue. · Medium confidence

Run flatnessBig climbs1.4
1,900 m (6,200 ft) of climbing in 43 km (27 mi), including El Yelmo, on a mountain trail. · High confidence

3.9Very good

Air temperature, how predictable the weather is, setting, and spectating. Counts for 15% of the overall score.

Air temperaturePleasant4.0
Typical air is 8-26 °C (46-79 °F): a cold pre-dawn swim and a warm afternoon, mostly comfortable for a May race. · Medium confidence
Weather reliabilityVariable2.9
The date has shifted between May and June across editions, and the swim may be shortened or cancelled. · Low confidence
Venue beautyStunning4.5
A natural park, the Tranco reservoir and a castle village. · Low confidence
Spectator friendlyTricky1.8
Remote loops, so spectators can realistically only watch at the castle finish. · Low confidence

Low altitudeModerate2.7
The start area is about 900 m (2,950 ft), and the passes likely climb above 1,500 m (4,900 ft); unverified. · Low confidence

2.8Good

Hotels, walkability, getting there, and the town around the race. Counts for 11% of the overall score.

Hotel availabilityBook early3.2
Small rural villages (Segura de la Sierra, Hornos, Orcera); no data. · Low confidence
Hotel valueGood3.9
Rural Andalusia pricing; no data. · Low confidence
WalkabilitySome driving2.5
The swim starts at the Tranco reservoir and the finish is in Segura village, about 20 km (12 mi) away; a car is needed. · Low confidence
Travel easeAwkward1.8
Remote Jaén mountains; the nearest big airport is Granada, roughly 2.5 hours (about 200 km (124 mi) / 124 mi) by road. · Low confidence
LogisticsFiddly1.8
A boat transfer to the swim start and a separate finish location. · Low confidence
Town and foodFine3.2
Small villages with Andalusian cuisine but limited choice. · Low confidence

Location: Embalse del Tranco / Segura de la Sierra, Jaen, Andalusia, Spain
Typical month: May
Latest or next date: 8 May 2027
Organiser: Independent (listed with global extreme triathlon calendar)
First held: 2021
Distances: 3.8 km (2.4 mi) swim, 180 km (112 mi) bike, 42.2 km (26.2 mi) run
Swim venue: Embalse del Tranco (reservoir)
Water temperature: 18–22 °C (64–72 °F)
Wetsuit: Mandatory
Swim start: deep-water
Bike climbing: 4,000 m (13,120 ft)
Key climbs: El Yelmo; La Cumbre (about 20 km); Despiernacaballos
Run climbing: 1,900 m (6,230 ft)
Run laps: 1
Air temperature: 8–26 °C (46–79 °F)
Altitude: 900 m (2,950 ft)
Nearest airport: Granada (GRX) or Albacete/Alicante options; exact nearest not verified
Where to stay: Segura de la Sierra, Hornos, Tranco reservoir area
Booking: Rural villages (Segura de la Sierra, Hornos, Orcera); town website has accommodation section. No race-specific advice found.

El Semanal de la ManchaRaced 2026 · article · Positive
Local-news report on a pairs winner in the 2026 race. Calls it among the most demanding endurance events in Spain in a striking natural setting; gives 3.5 km (2.2 mi) night swim, 175 km (109 mi) with 4,000 m (13,100 ft), 43 km (27 mi) trail with 1,900 m (6,200 ft). No participant quotes.
ManchainformacionRaced 2026 · article · Positive
Similar press report: night swim in near darkness, four major passes, 43 km (26.7 mi) mountain trail, described as one of Spain's most extreme Ironman-distance races. Notes a single mixed pair entered; no finish times or field size.
Running.life listingaggregator · Mixed
Listing only: night swim, mandatory wetsuit, 175 km (109 mi) bike with 4,000 m (13,100 ft), 43 km (27 mi) GR 247 trail. No athlete opinions.

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