First of 6,000 competitors embark in the iconic Blenheim Palace Triathlon

The first of 6,000 entrants have been swimming, cycling and running their way through one of Europe's leading triathlons.

This weekend marks the 20th edition of the Blenheim Palace Triathlon which takes place amongst the surroundings of the iconic Oxfordshire venue.

It's thought to be the the only event of its kind to be organised in the grounds of a UNESCO World Heritage site.

Organisers hope to attract new participants each year with competitors able to select a different level of pace.

The Super Sprint race consists of a 400m swim, 13.2km bike ride, and a 2.9km run while the Sprint race consists of a 750m swim, 19.8km bike ride, and a 5.4km run.

A relay, involving two or three people, will also happen over the weekend designed to make it easier for anybody not confident with completing a full triathlon.

For the hardiest of souls, the Weekend Warrior challenge allows competitors to take on as many triathlons as possible.

Ian Allerton, one of the organisers of the triathlon, said, "The nature of it being in the grounds itself, there's no traffic and no road closures, it's a really pleasant, calming environment. It's not an inter-city triathlon which can feel more challenging at times.

"We always see this event, particularly this year, with a really good first time feel. It's a really enjoyable one to do, particularly with the grounds and all the activity we have to enjoy once they've done it."

The triathlon is a fundraising opportunity with more than 300 charities supported by donations generated by participants.

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