The Series

The Festival of Endurance

Sunday 7th July 2019 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.

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The Festival of Endurance

Sunday 7th July 2019

We are pleased to announce that the Festival of Endurance will return on Sunday 9th July 2019.

Due to popular demand the Gauntlet half iron distance triathlon is returning with athletes racing alongside the full iron distance or Bastion competitors around much the same course.  Whilst these two epic triathlons are taking place a further 4 sets of endurance challenge races are taking place including an Aquabike, an Aquathlon, Long Distance Running and Long Distance Swimming making this a true celebration of the art of “going long”.  Please read on for more details.

2018 Results

Find your results here.

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.

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 the year.

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 Marathon

26.2 miles

After the huge success of the inaugural event in the 2018 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 2019 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

The Hever Long Distance Swim


  • 1.9k circuit
  • 3.8k circuit
  • 10K Marathon Swim (NEW in 2018) Entry tickets available to Individuals and Relay team of 5 (each team member takes on the 2k loop 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.

2019 Race distances and pricing

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

*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.

Course maps

Please take a moment to study these in details.

The Festival of Endurance at Hever Castle is an exciting and busy event with lots of different courses taking place throughout the day. There will be a full brief before your race start but it’s a good idea to familiarise yourself with the course and in particular any key junctions to ensure you take the correct route.

2017 Race Results

Useful information

Preparation for the event

The 2018 Competitor Guide, tailored for the Festival of Endurance at Hever Castle guides the competitor through the preparation for the event.

FOE Competitor Guide 2018
BASTION Competitor Guide 2018
Race licence

The Castle Triathlon Series UK events are governed by the British Triathlon Federation and their technical officials will provide guidance on the day and in the run up to the event.

On race day, all participants involved in a multi-discipline sport are required to produce a valid triathlon governing body membership card or purchase a Day Licence. The Day Licence fee is £5 Adult £1 Child and can be purchased at Registration on event day.  More information here

Spectator Offering

The spectator experience at the Castle Triathlon Series has become almost as famous as the spectacular backdrops and classic courses, and has made passing time before your loved ones finish the race a thing of the past.

Travel, accommodation and directions to the venue

Click the link below to find out everything you need to know about all of our venues.

Water quality

Please see the latest water quality tests for Hever Castle lake. All tests are undertaken using the EU Water Bathing Directive as the benchmark.

Water temperature

This will be taken nearer the Event, and posted on the Race Admin page.

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.

Find out more


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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