PERHAPS the most unexpected thing was the mud. The accepted view of Ethiopia is of a parched desert land, where drought and famine are regular visitors. So for Paul Brockway, the mud came as a bit of a surprise.

"People imagine it being very dry, but a lot of Ethiopia is at a high level, and it is not really a dry, dusty bowl," he says. "There aren't many tarmacked roads, so in the wet season when it rained every day, it turned into a mudbath. And even on the roads, so much mud washed on that they were pretty bad. You just had to roll your trousers up and change your shoes when you got to work."

Paul and wife Hilary have just returned from Ethiopia, working on placements organised by the charity Voluntary Service Overseas (VSO), Paul as a university lecturer, Hilary running HIV/Aids projects.

Seven years or so after leaving university, they had good jobs and a house in Durham, but decided to put it all on hold for two years.

"It is something we had talked about for quite a long time," says Hilary, 30. "We waited until we had done a few years of work and we felt we had some skills to offer, and we liked the idea of living in another country and another culture."

"We just felt the time was right for us to put something back," adds Paul, 31. "I know it sounds nave but that was what really drove us and it was the right time for us to go through with it."

After investigating different options, Paul and Hilary plumped for VSO, which offered longer-term placements than some other organisations, and the chance to work in development, rather than humanitarian, work.

Both were accepted as volunteers, and underwent training before they were offered placements, including on how to adjust to living in a different culture, and what to expect.

"The idea is to try and make sure you are as prepared as possible before going out, and as realistic as you can be," says Paul. "Rather than saying you are going to change the world, you are going to do what you can and you can't do any more.

"They also want to make sure people are going for the right reasons. Some people might be having problems with their marriage or their job, or they need some time off, but there are much easier things to do than VSO."

VSO was initially unable to find placements for the couple in the same place, so when Paul was offered a job teaching engineering in Jimma, a university town about 350km south of Ethiopia's capital, Addis Ababa, Hilary decided to go along as an accompanying partner. At first she found work for herself, teaching English and also physics, but after five months she was offered a VSO post co-ordinating HIV/Aids projects.

VSO was already involved in a number of small HIV/Aids projects, but wanted to expand its work. Hilary's task included generating income to support projects, helping people with Aids to set up their own businesses, and increasing awareness of the dangers of HIV.

"There is a lot of stigma, even in the big cities, where they associate it with prostitution," she says. "It is very hidden that people have sex outside marriage. It's as if it doesn't really happen, even though they know it does. And even when there is a high level of awareness, there can be limited behavioural change: people think it won't happen to them."

The level of stigma is such that few people are willing to talk about HIV/Aids publicly, and victims are often said to have died of other causes, such as TB, rather than Aids.

But this approach has also helped HIV spread through the population at a fearsome rate. In one clinic, blood samples showed around one in five pregnant women were infected, and in some hospitals around half of all patients are HIV positive. The prevalence of female genital mutilation in some parts of Ethiopia also encourages the spread of the virus.

For Paul, teaching engineering in one of Ethiopia's six universities, the obstacles were more practical.

"We had three overhead projectors for the whole faculty, and occasionally the electricity would go off. They had a diesel generator, but there might not be enough diesel, so in my first semester I taught everything on the blackboard, so I didn't need electricity," he says.

"There was also one person designated to do the photocopying, so we couldn't turn up if they weren't there, or if there was no electricity."

But the greatest adjustment was to the way of life in Ethiopia. Even though their house was not typical of those for ordinary Ethiopians, it was still a long way removed from their life in the North-East.

"We had running water and electricity, although sometimes both of those would go off," says Hilary. "In the first year, we had electricity cuts quite a lot, maybe two days a week for a whole day at a time, and sometimes it would just go off and then come back on again. In the second year, they built a new dam and that improved the situation.

"Some days there would not be enough water pressure to get any water out. Three days was maybe the longest we didn't have any water, but I know people who had to collect their water every day, so it was not as hard as it could have been."

But the shortages of water and electricity were not the biggest hardships the couple faced during their two years in Ethiopia.

"Learning to live your life out there is a big adjustment," says Paul. "You get a lot of attention. In Jimma, there are some 100,000 Ethiopians and maybe ten white people, who they call Ferengi.

"Whenever we went outside people would look at you. Some people would say stuff. Sometimes it was nice and little kids would come up and practice their English; sometimes it was not so nice, but I think you would get that anywhere."

For Hilary, this attention was one of the hardest things about living in Ethiopia.

"You couldn't go outside the door without people knowing who you are and what you are doing," she says. "If we were in a smaller place people would have got to know us, but we were in quite a big place. I have had mothers bringing their children out and pointing as we went past."

Although there are fewer calories in the Ethiopian diet, and both Hilary and Paul lost weight during their two years abroad, all the food is fresh, with nothing processed. Few cars mean walking just about everywhere.

With no television, the radio and the BBC World Service became a lifeline, but good Internet access and regular post helped the couple keep in touch with family and friends at home.

"The pace of life is much slower there. It was nice to get out of the rat race, just to take time out and get a bit of perspective on the world," says Paul.

The downside of this, however, is that when they returned to Britain late last year, they found it difficult to readjust.

"In Ethiopia, if you go into a shop and you want to buy some oil for cooking, there will be only one type of oil and one container, whereas here... " says Paul.

"I have left shops here without buying something because it is just so strange," adds Hilary. "There are so many people."

Their placements also gave them time to explore the country, trekking in the mountains in the north, exploring the villages in the south, hoping their interpreters would get lucky with some of the 80 languages spoken in Ethiopia.

"It is just such an amazing country, there is so much to see," says Paul. "When you think of Ethiopia, you think of Band Aid, you don't think of all the things we saw."

"It is quite different travelling when you have got some knowledge of the country," Hilary adds.

Paul took leave of absence from his job with Arup in Newcastle, and the couple rented out their house in Durham, but since returning have sold up and bought a new place in Newcastle. Hilary left her job, and is now working for Northumbria Training, which works with refugees.

But although they are settling back into living in Britain, their experience in Ethiopia has left an indelible mark.

"It has changed the way we view the world, and it has changed the way we see Ethiopia," says Paul. "Hopefully, we approach things in a different way because of it. I don't think you can go through that experience without it having changed you."

"Maybe before we went I would be more worked up about things, but in Ethiopia it is impossible to be like that, because things don't go the way you have planned and you have to be a bit more relaxed," says Hilary.

Although it took a substantial amount of preparation - they were planning their trip for at least a year - and there was little room for luxuries in their 30kg baggage allowance, both Hilary and Paul have no hesitation in recommending it.

"It is not something to rush into, but if it is carefully thought out and it is what you really want to do, it is a wonderful opportunity," says Paul.

"It was a difficult experience, it was hard to adapt, it was challenging, but it was just the most tremendous, remarkable two years you could ever spend."

* For information about volunteering, call 020 8780 7500 or visit www.vso.org.u