The Holy Loch is a sea loch in Argyll and Bute, Scotland. Robertson's Yard at Sandbank, a village on the loch, was a major wooden boat building company in the late 19th and early 20th centuries. During World War II, the loch was used a submarine base. From 1961–1992, it was used as a US Polaris nuclear submarine base. In 1992, the Holy Loch base was deemed unnecessary following the demise of the Soviet Union and subsequently withdrawn. Open to the Firth of Clyde at its eastern end, the loch is approximately one mile wide and between two and three miles (5 km) long, varying with the tide. The town of Dunoon on the Cowal peninsula lies on the shores of the Clyde just to the south of the loch, and houses continue round the villages of Kirn, Hunter's Quay at the point with the landing slip for Western Ferries, Ardnadam and past Lazaretto Point, the village of Sandbank, with open countryside at the end of the loch, then on the northern shore Kilmun, and at Strone Point the village of Strone continues round to the western shore of the Clyde, almost joining Blairmore on Loch Long. The name Holy Loch is believed to date from the 6th century, when Saint Munn landed there after leaving Ireland. All the villages used to have piers served by Clyde steamers, and now Western Ferries runs between Hunters Quay and McInroy's Point on the outskirts of Gourock, while the Caledonian MacBrayne service runs from Dunoon to Gourock pierhead. At the end of the loch a road runs past the Benmore Botanic Garden and Arboretum (also known as the Younger Botanic Gardens) to scenic Loch Eck and on towards Oban.