The walk starts from the northern end of Heatherdene car park on the A6013 beside Ladybower Reservoir (S33 0BY), which is run by Severn Trent. It's pay and display: £3.50 for up to 2 hours, £6 for 2 to 4 hours or £7 for over 4 hours, so for this walk of 4 to 5 hours you'll need the over 4 hours ticket. You can pay by cash or card at the machines or with the RingGo app (zone 58250). The car park is open in daylight hours only, with no overnight parking, and closes in extreme weather. It's popular, so arrive early at weekends. There are toilets in the car park. Check the latest prices here.

The quiet track up the east shore once led to a real village. Derwent stood in the valley here, with the 17th-century Derwent Hall, a church and a packhorse bridge over the river. Its neighbour Ashopton sat at a crossroads on the main road between Sheffield and Glossop, near where the A57 viaduct crosses the water today. It had a large coaching inn, a post office, a Methodist chapel built in 1840 and a wool fair every July.

Both villages were bought by the Derwent Valley Water Board to make way for Ladybower Reservoir, and the people who lived there had to move to new homes. The last service in Ashopton's chapel was held on 25 September 1939, and the last at Derwent church on 17 March 1943. Bodies were taken from Derwent churchyard and buried again at Bamford, the church bell was later hung in St Philip's Church at Chaddesden in Derby, and the packhorse bridge was taken down stone by stone and rebuilt at Slippery Stones, at the head of Howden Reservoir. The buildings that would end up under the water were knocked down before the reservoir filled.

Only Derwent's church spire was left standing, as a memorial. It stuck up out of the reservoir until 15 December 1947, when it was blown up because it was thought to be dangerous. In very dry summers the water still drops far enough for the ruins of Derwent to appear, as they did in 1959, 1976, 1995 and 2018, and thousands of people come to walk among the old walls and floors.

Long before the reservoirs, people farmed and buried their dead on Crook Hill. About 330m north-west of Crookhill Farm, which this walk passes through, is a small Bronze Age stone circle. It is roughly 7m across and made of five small stones: two still stand, about 0.4m and 0.6m high, and the other three lie flat. Inside are two patches of grass-covered rubble, so the stones may once have been the kerb around the edge of a cairn. Only digging could tell which, and it is a protected Scheduled Monument.

Nobody fully understands what stone circles like this were for. They were clearly important for ritual, and when they have been excavated they have often been a place for burials. Some may have been lined up with the sunrise or sunset at midsummer or midwinter, and others may have been meeting places for local groups. Circles were built from the late Neolithic to the middle Bronze Age, roughly 2400 to 1000 BC.

There are burial mounds too. One round cairn lies in the saddle between Crook Hill's two rocky tops, with views over both the Derwent and Woodlands valleys. Another lies west of the northern top, and close to it is a small pile of stones thought to have been cleared from the ground to make it better for farming. Round cairns were heaped over burials placed in stone-lined boxes called cists, and together these remains show that Bronze Age people both lived and held ceremonies on this hill.