Castle Stalker (Scottish Gaelic: Caisteal an Stalcaire) is a four-storey tower house or keep picturesquely set on a tidal islet on Loch Laich, an inlet off Loch Linnhe. It is about 1.5 miles (2.4 km) north-east of Port Appin, Argyll, Scotland, and is visible from the A828 road about mid-way between Oban and Glen Coe. The islet is accessible (with difficulty) from the shore at low tide.