Yachtswoman Rosie Swale Pope will mark her 57th birthday by setting off to run around the world - 30 years after she circled the globe by sea.
Rosie Swale Pope is hoping to be back home in 18 months
The adventurer will be travelling without a support team and will carry everything she needs in a back pack.
She aims to be back at her Pembrokeshire home in 18 months.
She has taken on the challenge to raise funds for a Russian children's home in Kitezh and to raise awareness of prostate cancer after the death of her husband Clive.
"I'm very excited," she told BBC News Online.
"I wanted to do something newsworthy enough to raise awareness of prostate cancer.
"My husband died last year and it was a case of had we thought about it early enough he could probably have been cured.
"To be away for so long will be a huge sacrifice because I love my home and family so much but if you have a happy life it inspires you to do new things."
25 miles a day
She will set out from Tenby on 2 October - her 57th birthday - and will run through Holland, Germany, Poland and Estonia with the aim of entering Russia on New Year's Day.
Her 20,000-mile journey will then take her into Canada, across Greenland, Iceland and Ireland before she gets to put her feet up back at home.
"The first day I'm trying to cover the 30 miles to Carmarthen but on average I'm hoping to do 25 miles each day.
"Some days will be less as I will need a bit of a rest and some days there will be things to see and learn."
He back pack will weigh about 13 kilos and she will buy food as she goes.
"It has all been well thought out," she said.
"But I am unpacking and packing my backpack each day at the moment to try and get it as light as possible.
"I'll be sleeping in a tent most nights as I don't want to impose myself on people and also for reasons of economy.
"For the first part I will be buying food as I go but I will have to carry supplies when I reach Siberia."
Rosie's son James has set up a website on which he will regularly up-date his mother's progress and she said her daughter Eve and the rest of her family and friends had been very supportive in helping her prepare.
Thirty years ago Rosie and her first husband Colin sailed around the world.
She has also completed a 3,000-mile horse trek down the coast of Chile, run across the Sahara desert and competed in dozens of marathons.