Holy Loch

Holy Loch An Loch Sianta/Seunta
The Holy Loch seen across the Firth of Clyde from Tower Hill, Gourock, with Hunters Quay on the left and Strone to the right.
Location	Cowal, Argyll and Bute, Scotland.
Coordinates	55°59′13″N 4°55′59″W / 55.987°N 4.933°W / 55.987; -4.933Coordinates: 55°59′13″N 4°55′59″W / 55.987°N 4.933°W / 55.987; -4.933 National grid reference NS1713980778
Type	Sea Loch
Basin countries	Scotland, United Kingdom
Surface elevation	sea level
Frozen	No
Islands	0

The Holy Loch; (Scottish Gaelic "An Loch Sianta/Seunta") is a Sea Loch, a part of the Cowal peninsula coast of the Firth of Clyde, in Argyll and Bute, Scotland.

The "Holy Loch" name is believed to date from the 6th century, when Saint Munn landed there after leaving Ireland. Kilmun Parish Church and Argyll Mausoleum is said to stand where Saint Munn's church was once located.

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 as a British Royal Navy submarine base. From 1961–1992, it was used as a United States Navy Polaris and Poseidon nuclear submarine base. In 1992, the Holy Loch base was deemed unnecessary following the demise of the Soviet Union and subsequently closed.

Open on the Firth of Clyde at its eastern end, the Sea Loch is approximately 1 mile (1.6 km) wide and between 2 and 3 miles (3 and 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, Hunters 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 Sea Loch, then on the northern shore Kilmun, and at Strone Point the village of Strone continues on the western shore of the Firth of Clyde, almost joining Blairmore on Loch Long.