Teams of walkers will be climbing Britain's 100 favourite hills and mountains (as compiled by Trail's panel of experts) to raise £200,000 towards WaterAid's work providing safe, clean water and sanitation to the world's poorest people.

The event takes place on Saturday, June 7 when teams from across the country will to be reaching the top of their chosen summits between 12pm and 2pm.

"We put the Trail 100 Challenge together specifically to encourage people to get out of their walking rut and visit new areas," says Trail Editor Matt Swaine. "So this is a great chance to climb that dream hill or just head somewhere you've never been before, plus of course, it's all for WaterAid."

WaterAid is calling for more local hikers to take on the Challenge. Not surprisingly, many of the most favourite mountains are to be found in the Lake District, and most already have teams signed up for.

However, there is still two mountains that no-one has registered: namely, Black Combe at 600 metres described by Trail as 'the first rampart of England's greatest mountain heartland' and High Pike at 658 meters, described as 'the best excuse to visit here'.

To register to for these two walks or for more information on the WaterAid Trail 100 Challenge visit www.wateraidtrail100.org or tel: 0845 120 1293.

"Walking is a particularly appropriate theme for our charity", explains Fran Critchley of WaterAid. "Often women and children in the countries where we work need to walk for miles and hours just to obtain their vital daily water. This time could be better spent at work or school enabling them to help themselves out of the poverty trap."