From the organisers of the Castle Triathlon Series, the 226km Bastion has swiftly become known as one of the toughest long-course races in the UK. The fifth edition is now open for registration, with early bird prices seeing a 25% discount.


The event has gained a strong reputation as a nurturing and friendly event, which is documented on Racecheck where it scores 4.7 out of 5.0, with one competitor describing it as “one of life’s defining races.” Further endorsement comes from the loyalty stats of the competitors taking part, in its third year 36% of the competitors were competing for the third time. 

The exclusive field of triathletes compete alongside the Hever Castle Festival of Endurance, which features over 1,000 competitors and thousands more spectators, with its offering of multiple races (including single swim events and an aquabike) and a course for various distances and training opportunities.

Bastion entrants will receive a personal walk of the event village and course guidance from the Race Director, Brian Adcock, with the spectators set to enjoy the castle grounds, village pubs and live music and children’s entertainment in the event village.

Read course tips on conquering the Bastion here

The lapped course and athlete tracking means competitors can be seen regularly and supported as they complete their 226km goal. The event organisers have created cheering zones for the participants, and also offer competitor support with a team member allowed to join any last runners for the final 10km stretch to keep them on a high for their finishing line moment.