The district of Strath Errick and Foyers, with which the investigation recorded here is concerned, occupies about 70 square miles southeast of Loch Ness, in Inverness-shire. The ground rises steeply from the loch to form a bordering ridge, beyond which it slopes more gently to Strath Errick. Further to the south-east, the hills rise to a height of 2,560 ft. in Beinn Bhuraich. The country is chiefly moor and hill grassland, with numerous exposures of rock; fairly extensive areas are under arable cultivation in Strath Errick. The district is drained by the Rivers Fechlin and Farigaig, both of which enter Loch Ness through deep gorges (Text-fig. 3).