Achnacarry is a hamlet, private estate, and a castle in the Lochaber region of the Highlands, Scotland. It occupies a strategic position on an isthmus between Loch Lochy to the east, and Loch Arkaig to the west.

The Commando Basic Training Centre was a British Army training establishment primarily for the training of British Commandos during the Second World War. It was located in the grounds of Achnacarry Castle in the Scottish Highland region of Lochaber.