Loch Shiel is a freshwater loch situated 20 kilometres (12 mi) west of Fort William in the Highland council area of Scotland. At 28 kilometres long it is the 4th longest loch in Scotland, and is the longest to have retained a natural outflow without any regulation of its water level, being 120 m (393 ft) deep. Its nature changes considerably along its length, being deep and enclosed by mountains in the north east and shallow surrounded by bog and rough pasture in the south west, from which end the 4 km River Shiel drains to the sea in Loch Moidart near Castle Tioram.

Castle Tioram is a ruined castle that sits on the tidal island Eilean Tioram in Loch Moidart, Lochaber, Highland, Scotland. It is located west of Acharacle, approximately 80 km (50 mi) from Fort William. Though hidden from the sea, the castle controls access to Loch Shiel. It is also known to the locals as "Dorlin Castle". The castle is a scheduled monument.