This walk should only be undertaken in clear weather with no cloud on the hill. There are also some awkward points as you descend a gorge, having to cross and re-cross a small stream. This route is not recommended after heavy rain.
Start at the rough lay-by at the watershed of the Weisdale to Tresta road. Take the track which leads straight up to the ridge and the masts. This is a stiff climb to start with but the views from the summit are magnificent. There is some peat hags at the top. Head along the ridge, towards a cairn on Weisdale Hill avoiding the boggier stretches. The Watch-house Loch here was said to have been the site of a desperate chase during the Press Gang period in the Napoleonic wars.
If the day is fine, you can extend your walk by an hour by heading on to Atla Scord, a splendid vantage point to the North. The name Atla, was a legendary giant of Norse origin, and is found in several places in Shetland. There are fantastic views from here in clear weather. You can see virtually the whole of Shetland. To the west and south, the ground drops away, curving towards the catchment for the Burn of Tactigill. You can descend towards the stream to follow this glacial drainage channel back to the main road.
Several small streams merge as they drain the moors, entering the gully, which soon becomes a perfect little Shetland gorge. There are little waterfalls, but you can scramble down beside them, if the flow is not in spate. After a while the stream begins to meander, looping back and forth across the valley floor. Soon you are forced to cross and re-cross the burn in order to stay on the rough green path. There are several places where the valley widens out and there are some beautiful miniature meadows, filled with wild flowers in summer.
At a few points, the stream cuts into the face of the gorge, revealing bands of rather soft, cheese like rock forming strata of several different coloured bands. This is weathered granite, which has had certain water soluble minerals washed out of it by water drainage over the ages.
The soft clay like rock is said to have had the properties of China clay and came to the attention of Wedgwood early in the last century. It was apparently tested and investigated, but hadn't sufficient quantity to merit developing into a quarry. Had a pottery business been set up, this exquisite little valley would have been destroyed.
In some of the wider level stretches between meanders, there are traces of turf dykes and stone walls, suggesting small buildings or activities carried out in the past. Eventually the valley opens out and you come to the main road above Tresta. From here it is an easy walk back uphill to the starting point.