A group of runners are starting a 260-mile challenge to raise money for Lakes Youth Charity.
The team of 12 are running 26.2 miles around Windermere every day for the next ten days.
At the start of their first Marathon today, they're being waved off by the event's patron Jos Naylor.
Over 900 people have raised over £90,000 for the Brathay Trust in Ambleside by running the Windermere Marathon.
The runners included 14 who ran the same marathon every day for 10 days - what's known as the Brathay 10 in 10.
Fiona Marley Paterson reports:
Runners from across the country are meeting in the Lake District today to begin the first of a gruelling ten Marathons.
They each will run the equivalent of ten marathons in ten days. The course is set around Lake Windermere and each runner will have to complete ten laps of it to reach their total.
It's the eighth time the race has taken place in the Lakes.
One of the world's most gruelling foot races began in the Lake District this morning.
Competitors will run a marathon a day around Windermere until next Sunday as part of the Brathay ten in ten challenge.
Fifteen runners were selected for the charity event, which is widely regarded as one of the ultimate tests of endurance.
Ryan Dollard reports:
To find out more about the work Brathay Trust does, and how you can sponsor competitors, visit the website here.
61-year-old John McCann is the oldest competitor taking part in the Brathay Trust marathon, and he knows he is going to have to pull out all the stops to complete the monstrous challenge:
Legendary Cumbrian fell runner Joss Naylor says that the Brathay Trust marathon is no mean feat:
Mike Bushell from the Brathay Trust believes that the Windermere marathon is arguably the toughest in the world:
A group of runners are about to begin an epic marathon challenge that will see them tackle ten marathons in ten days.
The Brathay Trust Windermere 10in10 Marathon gets underway at 9.30am from Brathay Hall in Ambleside.
Fifteen competitors are due to take part in one of the most daunting endurance runs in the world.
Runners will pound their way over 262 miles of Windermere roads and pavements to raise money for charity.