Castle Varrich was the ancient seat of the chiefs of Clan Mackay - the most powerful Highland clan in this corner of Scotland, whose territory ran from Assynt to Cape Wrath, Loch Shin to Strath Halladale, in a swath known for centuries as Mackay Country. Tradition holds that caves under the castle were once inhabited by the Mackays themselves, before the keep above was raised. The most likely sequence is that an early Norse settlement claimed the rock during the centuries when the north coast of Scotland was Viking ground; the Mackays then took over and rebuilt in the 14th century, dressing the old foundations with the metamorphosed sandstone they could quarry from the nearby cliffs. Eventually the chief's seat moved down the hill to Tongue House - a less defensible, more comfortable address - and Varrich was abandoned to the sheep and the wind.

The keep had two floors plus an attic, but here is the curiosity: there were no internal stairs between the floors. The ground floor was entered through a door on the north wall and was probably used as stables for horses or cattle. The upper floor had its own entrance on the south side, accessed by a ladder or removable stair - the medieval equivalent of pulling the drawbridge up at night. A window faced east. A fireplace warmed the west wall. Both have now collapsed past recognition. The arrangement only makes sense as defence: an attacker who got inside the ground floor was trapped there with the animals while the family pulled up the ladder and waited out the siege from above. The view from the upper floor takes in Ben Loyal and Ben Hope - 764 and 927 metres of granite, immediate landmarks of warning whenever a war party crossed the high ground.

In 2017 the castle was given a careful and slightly surreal modern upgrade. A galvanised steel spiral staircase now climbs through the interior, and a viewing platform at the top lets visitors look down over the Kyle of Tongue from roughly the height the medieval upper floor would have occupied. The 19th-century approach of leaving ruins to crumble picturesquely has been replaced, here, by a working compromise: the original stones are protected, the public can climb, and the view that the Mackay chiefs once watched for trouble can now be admired by anyone who walks the marked footpath up from the village of Tongue. It is a short hike - signed, well-trodden, and about an hour each way - and the panorama from the platform takes in the bridge across the Kyle, the village below, Ben Loyal to the south, and the wide curve of the kyle running north to the open sea.