More than 750 people in Guernsey are taking on the Everest Challenge during January.
The walkers and runners are doing 115 laps of the Valle de Terres in St Peter Port, which has a gradient of 77 metres.
It is a gruelling slog and everyone is doing it to raise money for the Sarah Groves Foundation.
If they each raise £1 per lap, the charity is on course to raise more than £85,000.
The charity is named after Sarah Groves, who was travelling through Kashmir in April 2013 when she was stabbed to death on a houseboat.
A Dutchman, Richard de Witt, has been on trial for murder now for seven years.