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 Bastion - Full iron distance

The iconic endurance challenge kicks off with a 3.8km lake swim before a 180km looped  bike course around the Kent countryside. A 42km marathon run completes what is ‘one of life’s defining races’.

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The Bastion - Full iron distance

Hever Castle, Kent

We are delighted to announce that The Bastion full iron-distance triathlon will be back, for the fifth time, on 8th July 2018.

The nurtured exclusive field continues to shows loyalty and grit and we look forward to welcoming them back along with new competitors ready to take on the challenge.

Bastion Hever Castle Triathlon Long Distance Half Iron

Register your Interest

Are you interested in The Bastion, but not quite ready to commit? Share your email address below to receive more information about The Bastion and preparations for a long distance event with the Castle Triathlon Series.


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About The Bastion

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, features a 3.8km river and lake swim, a true toughie of a 180km bike course with 3,000m of climbing and a 42.2km run course that takes place largely off-road including running through the grounds of the beautiful Chiddingstone Castle. The event has generated rave reviews, helping grow this event into one of the truly iconic long distance triathlons in the world.

220 Triathlon has listed The Bastion as a ‘must-do’ race in 2017.

The event scores 4.7/5 on RaceCheck. See reviews here. 

Get a taster of The Bastion course

Bastion Training Guides

thetrilife.com have designed training plans depending on level of experience of a triathlete and tailored specifically to the  Full Iron ‘Bastion’ distance triathlon.

Course Maps

Please take a moment to study these in details.

The Bastion is an exciting and busy event with lots of different courses taking place throughout the day. There will be a full brief the day before your race 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 Results

This section will provide you with the 2017 race time results.

The Bastion was quite simply the best event I’ve ever done. The course was immense; brutal, but brilliant. The venue was unique; an inspiring backdrop and great fun for spectators.
Dan Cliffe
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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