Pop-up City Triathlon

Lough Cutra Castle
26/27 May 2018

Cholmondeley Castle
23/24 June 2018

The Festival of Endurance at Hever Castle
8 July 2018

Castle Howard
21/22 July 2018

Château de Chantilly
25/26 August 2018

Hever Castle
22/23 September 2018

Schools Roadshow
July 2018

The Series

The Festival of Endurance

Sunday 8th July 2018 promises another exhilarating and atmospheric celebration of ‘going long’ at the iconic and stunning Hever Castle. Loved by competitors and spectators alike the event is hailed the most friendliest and beautiful on the tri radar.


The Festival of Endurance

Sunday 8th July 2018

We are pleased to announce that the Festival of Endurance will return in 2018, 8th July.

Due to popular demand, the Hever Gauntlet half-iron triathlon will be held bi-annually giving triathletes the option to race alongside the full iron-distance Bastion competitors on 8th July 2018. Whilst these hardy triathletes battle their way around this iconic course, we shall host a further three challenges for those looking for an opportunity to ‘go long’.  Please read on for more details.

2018 British Triathlon Middle Distance Championship


We are delighted that the middle distance, otherwise known as The Gauntlet half iron,  has been awarded with the 2018 British Triathlon Middle Distance Championships.

The Bastion

3.8km/180.2km/42.2km – Full iron distance race.

Set within close proximity to London and triathlon’s heartland of the south-east, each leg of The Bastion has been carefully designed to offer the ultimate challenge for both newcomers to long-distance triathlon and experienced long-course hands. The Bastion, the final stronghold of a medieval castle, will feature a 3.8km river and lake swim, a true toughie of a 180km bike course with 2,000m of climbing and a 42.2km run course that takes place largely off-road including the beautiful grounds of Chiddingstone Castle. Following a huge success in 2014 generating rave reviews, the iron distance men and women enhanced the experience in 2015 contributing to growing this event into one of the truly iconic long distance triathlons in the world.

The Gauntlet

1.9km/90km/21km – Half iron distance race.

The Festival of Endurance at Hever Castle will host the 2018 British Triathlon Middle Distance Championship.

This middle distance course is made for a National Championship with the 1.9km swim will involve a single loop taking in the main Hever Castle lake and a tributary of the river Eden (being dredged in Autumn 2012 & 2013).  The 90km cycle (2 loop course) winds its way through the stunning High Weald of Kent and the Ashdown Forest.

Click here for cycle elevation route

The 21km run course is 2 loops of 10.5km, will take in the existing 5km Hever Castle Triathlon course but with a 5km extension via tracks and bridle paths though the historic local village of Chiddingstone. The course includes a strong off road element which allows a highly inspirational setting often praised and welcomed by the elite triathletes.

Click here for run elevation route

Those athletes that become the British Triathlon national champion in their age group will automatically pre-qualify to the 2019 ETU Middle Distance Triathlon European Championships! Please note to be eligible for a National Championship medal, you must be a member of British Triathlon. The results from this event can also be used for general Age Group selection to the 2019 ETU Middle Distance Triathlon European Championships by submitting your time after you’ve racedFind out more here.

Long course training distances

We are offering you the chance to swim, bike or run sections of The Bastion, arguably the most grueling Full Iron distance course on the planet. Fully timed and fully supported just like those taking on the iron-distance race alongside you.

The perfect training ground to prepare for any iron-distance challenge or to get an idea of what might await you next year should you return for the ultimate Castle Triathlon Series challenge and take on The Bastion in 2019. This is a fantastic training race set in a stunning location in mid-summer, perfect for those taking on an iron-distance in the second half of 2018.

The Hever Marathon

26.2 miles

After the huge success of the inaugural event in the 2017 Series, the marathon returns to the atmospheric Festival of Endurance at Hever Castle.

Forget the city marathon, and fill your lungs with country air and stunning scenery before you conquer your marathon by a castle drawbridge. This new marathon, promises the most stunning off road course in the UK, a truly motivational and beautiful route that will distract you from the challenge itself. The four-laps take in two castles, two lakes, quaint Kentish villages, oast houses and with spectators and locals cheering you on all the way!

Marathon Pacer Timings : 4.00hrs, 4.30hrs, 5.00hrs, 5.30hrs (this is slower paced course than many road ones –  4.30hrs on this course is equivalent to a 4.00hrs on a road course!)

The Hever Half Marathon

13.1 miles

Take on the half marathon at our 2018 Festival of Endurance, on the most stunning off road course in the UK.

Starting at the drawbridge of the Hever Castle, this two-lap course takes in two castles, two lakes, quaint Kentish villages, oast houses with spectators and locals cheering you on all the way! Finish your race with a big celebration, medal and finishing line banquet in sight of the castle.

Half Marathon Pacer Timings : 1.45hrs, 2.00hrs, 2.15hrs, 2.30hrs

Run route maps and GPX file

The Aquabike Challenge


  • 1.9k swim: 60k cycle: 4k optional run (Laps 1:1:1)
  • 3.8k swim: 120k cycle: 4k optional run (Laps 2:2:1)

There’s a training option for everybody who’s into long distance.  After the unique swim you’ll head out on the fully marshalled and signed bike course with supported feed stations. This circular cycle route will take competitors out of Hever Castle, up through the High Weald of Kent before passing through and over the Ashdown Forest and into the village of Maresfield.  After a quick tour of the village competitors retrace their steps to the top of the forest before returning to Hever via the historic and quintessentially English villages of Groombridge, Fordcombe and Penshurst.  Finishers have the option of finishing with a gentle 4K run that circumnavigates the lake and stunning grounds of the Hever estate.

The Aquathlon Challenge


  • 1.9k swim / 10k run (Laps 1:1)
  • 3.8k swim / 21k run (Laps 2:2)

After the unique swim (1 or 2 loops), competitors will then embark on the 10k/21km run course, which follows largely off road tracks and bridle paths between Hever Castle, through the historic local village of Chiddingstone, before finishing right in front of the Castle.

The Hever Long Distance Swim


  • 1.9k circuit
  • 3.8k circuit

The swim course leaves from the Italianate loggia taking competitors down the length of the main lake and heading into the scenic river section.This tributary of the River Eden wraps around 16 Acre Island allowing spectators to watch and cheer competitors on from only a few meters away. The Speedo team will be on hand to welcome you at the finish, then it’s time to relax and enjoy a complimentary bacon roll back at the Event Village.

2018 Race distances and pricing

Race Name
Race Distance
Race Price
(Individual / Relay**)
Discount Prices
(Individual / Relay**)
Start time
The Bastion Iron Distance
Middle Distance Aquabike
1.9km swim / 60km bike (optional 4km run)
Long Distance Aquabike
3.8km swim / 120km bike (optional 4km run)
>The Gauntlet Half Iron Distance
Long Distance Swim
3.8km swim
Middle Swim
1.9km swim
Middle Distance Aquathlon
1.9km swim / 10km run
Long Distance Aquathlon
3.8km swim / 21.5km run
Full Marathon
42.2km run
Half Marathon
21.1km run

>2018 British Triathlon Middle Distance Championship

*Start times are approximate and shown here as a general guide. These are subject to change. Each distance start time is preceded by a brief by the Race Director.

**Relay options apply for Gauntlet and Bastion participants.

Entrants will be notified via email with full race details, including confirmation of wave times, 2 weeks prior to the event.

Race day information

Two weeks prior to event, this section will give you everything you need to know about race day, including wave times, registration opening details, spectator entry, camping info and water temperature readings etc.

2017 Race Results


Race distances

Race distances

For the absolute beginners and children to the professional triathletes, the Castle Triathlon Series offers a wealth of race distances to suit all levels.

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Hosted at a selection of stunning and iconic castles across the UK, Ireland and France, the Castle Triathlon Series events all promise an inspirational and memorable race experience.

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Take part

We pride ourselves on offering a bespoke and tailored offering for all those wishing to take part and grateful for all those who want to be involved on the day.

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We would always recommend training in preparation for any event, but how much you do, and the style you take is down to you.

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