By Kate McGeown
BBC News, Khao Lak
This time last year, Andy Brash had just finished his carpentry apprenticeship in Scotland, Patricia Byron was living in south London with the youngest of her eight children and Aaron Sangster was backpacking in Australia.
But that was before the tsunami. Now all three are living in Thailand, helping rebuild the resort town of Khao Lak, which was practically wiped out by the disaster.
Each has their own reasons for being here. For Andy, it was a suggestion from a friend, who told him the area was desperate for people with his newly-acquired carpentry skills.
Patricia was spurred on by her daughter Jody, who also decided to help in the tsunami relief effort. And Aaron planned to travel through the area briefly in early January, but has yet to leave.
"I just got into it - there was so much need. People were living in tents all around us: I didn't need much more motivation than that," he said.
Other volunteers have more personal reasons for spending the past year helping the huge reconstruction effort in Khao Lak.
Shonti Breisch, a 19-year-old from Utah, was on holiday with her family this time last year. The tsunami killed her sister and badly injured her brother.
After returning to the US, Shonti could not stop thinking about Thailand.
Andy Brash was able to use his skills to build Thai homes
"When something like that happens to you, you leave a part of yourself behind," she said.
"I almost felt we'd abandoned the Thais. We went back to our houses, our belongings, our jobs. We lost a family member but not everything we owned."
So she deferred her college course for a year and came back to Thailand. "I love being able to help people, and saying we can make things a bit better for them," she said.
Learning to build houses
Most people who arrive to help in Khao Lak end up at the Tsunami Volunteer Center, which was set up in the immediate aftermath of the disaster and is involved in numerous projects throughout the area.
VOLUNTEERING IN KHAO LAK
More than 3,500 volunteers over the year
Volunteers range in age from 19 to 67
More than 50 countries represented
Source: Tsunami Volunteer Center
During the past year, a steady stream of people from across the world have come to the centre to volunteer their services.
Many, like Jody and her mother, have spent much of their time rebuilding the homes of local people who lost everything in the disaster.
"I'd never done anything like this before, but now I know how to build a complete Thai house," Jody said.
"When I saw how happy people were with their new homes, I knew I couldn't leave until the whole village was done," she said.
In the first few months, there was an urgent need for homes, with tens of thousands of people living in tents and temporary shelters.
As time has gone on, the centre has become involved in other projects, from restoring boats for local fishing communities, to teaching in schools and helping improve the local environment.
Joa Keis, an American who has been in the region since February, has spent much of his time in Khao Lak teaching English.
"The most amazing thing for me has been the attitude of the children here. There are lots of empty seats in the classes, and the kids are still hurting, but they're still amazingly positive," he said.
Of course the volunteers are not the only foreigners in town. Before the tsunami, Khao Lak was home to people from many different countries, who made their living in the area's hotels, restaurants and shops.
Many of them decided to stay on after the disaster, despite the fact their livelihoods were in ruin.
"It never really occurred to me not to stay," said Sally Burbage, from the UK city of Bristol, who is the part-owner of the Sea Dragon dive shop.
"Khao Lak is my second home. I know a lot of the survivors, and the Thais needed to see that other people weren't running away," she said.
"It's better here than in England. It's easier to talk about what we all went through."
Volunteers and locals are working together to make new furniture
In the past few months, her dive shop has been getting busier as tourists gradually return to Khao Lak.
For locals and those who own businesses here, the increase in visitors is a welcome sign that the resort town they once knew is returning to normal.
But the volunteers have mixed feelings. For many, the sign that tourists are coming back is a sign that the time has come for them to move on.
Already the volunteer centre's emphasis is changing from tsunami relief to community development.
"There is still a need here, but the crisis is long finished. It's all redevelopment now," said long-term American volunteer Tilo Rau.
Many are staying for the anniversary commemorations on 26 December, and then planning to leave soon after.
But they will go home with very special memories.
"This has been by far the most challenging year of my life," said Tilo Rau. "It has definitely changed my whole outlook on things."
"Being here is a once-in-a-lifetime opportunity," added Aaron Sangster. "Everything else can wait. When I came here I thought: 'These people need help, and if I can give it to them I will'. And I've learnt so much from them in return."