This is a challenging walk to Castle Crag fort, but the reward at the top makes it all worthwhile. The fort was probably constructed during the first millennium BC. It stands on the hilltop and is thought to have housed one or two families and to have been defended by an earthen bank with a ditch in front. The bank may have had a palisade. Today it is an idyllic corner reached by a steepish climb.

Park in the small pay-and-display car park on the west side of Thirlmere dam, grid reference 307189.

1 Walk away from the dam, north, for a short way. Ignore an old stile and go on to take a set- back signposted gate on your left. Beyond walk the track for a few steps. Almost immediately wind left and climb steadily. The way is littered with dead twigs and the winter storms have damaged the surface. As the way begins to level and Raven Crag towers overhead, watch out for an easy-to-miss set of two deer gates giving access to a distinct narrow path ascending through dense conifers. Underfoot the path is reinforced but in dry weather the small stones act like ball-bearings. This path brings you to another pair of deer gates.

2 Beyond, cross a track and go on climbing the continuing path through the conifers and then beech. Well up the path lie several fallen trees, which are fairly easy to straddle. Just beyond are more obstructions and a tiny patch of bog. Once past these the path bears left and then right and climbs steadily upwards. It then winds right above a steep slope and on into an open area soon reach a wide track. Cross to take a kissing gate in a short fence onto a narrow path through a lovely open area. Descend gently to a reinforced way and then a footbridge over a wide gill. Ahead you can spot the signboard directing you to the fort.

3 Ahead are two little paths. The left one leads you under the huge crag and, suddenly, to the edge of the huge drop into the dramatic Shoulthwaite Valley. Beyond, tower the steep slopes between High Seat and Bleaberry Fell. Return from the edge and wind around the crag and climb up. Enjoy the magnificent views. Perhaps pause here in this sheltered spot, at the foot of the crag, for your lunch break and look for the earthen banks and the ditches.

4 Return along the path to take the kissing gate onto the wide track and walk left. This winds around in great bends, to ease the gradient, below The Ben. The way passes beneath well-spaced Scots pine, allowing in light for a fine under-storey of plants. Remain on the track as it nears the valley and curves right.

5 Follow it, right, along the valley – a level way at last – to reach the narrow road via two gates. Turn right and a short way along take the signed track, left, to pass between the restored barns and the old farmhouse at Smathwaite. The track continues beyond and drops downhill beside a fence on the right. It then winds right to cross an interesting footbridge. Ascend by the wall on the right to pass through a gate. Follow the way as it continues through the outbuildings of Low Bridge End farm to join the road. Turn right and cross the dam at the head of the reservoir to regain the parking area.

Information Distance: 5 miles Time: 3-4 hours Terrain: Very steep at first and you may prefer to climb the track used in this walk for the descent, which is also steep but well graded and surfaced.

Maps: OS Explorers OL 4 and 5 NB: Restrictions on space mean that this article provides a general summary of the route. It is advisable for anyone who plans to follow the walk to take a copy of the relevant Ordnance Survey map.