Rosie Swale-Pope, 61, had started her odyssey around the globe on her cart in 2003.
The granny of two received euphoric welcome with hundreds of well-wishers out on the road to cheer for her as her journey came to an end.
Swale-Pope described her journey as "just a fun run that's got out of hand".
"I can't believe you've all turned out for me. I'm overwhelmed. It's a journey that came out of sorrow and pain and heartache, but it's a journey that has turned to joy," Times Online quoted her as saying.
"Thank you for the most beautiful welcome anyone could have. This is a dream come true, and I hope everyone's dreams come true," she added.
Swale-Pope had pains in her legs caused by stress fractures that compelled a stay in a Haverfordwest hospital, and she hobbled the last stretch of her journey on crutches.
She said that she hoped that the project would help highlight the importance of early cancer screenings.
"The death of my husband, Clive, from prostate cancer taught me more than anything about how precious life is, how short it can be - that you have to grab life, do what you can while you can, and try to give something back," she said.
"If I can spread the message to people to get checked out, all this will have been worth it," she added.
In the 1980s Swale-Pope sailed solo in a yacht across the Atlantic. She has run across the Sahara and ridden through Chile on horseback.