Eilean Musdile is an islet, and lighthouse to the south west of Lismore in the Inner Hebrides.
The island lies in the entrance to Loch Linnhe, separated from Lismore by a sound ¼ miles across. It is a low-lying rock, ten acres in size, with some grass on it. CalMac ferries pass close to the island on their way from Oban to Mull.
The lighthouse was built by Robert Stevenson in 1833 at a cost of £4260 and initially showed a fixed white light. In 1910 most of the Northern Lighthouse Board's lights were changed to dioptric or Fresnel lenses but Lismore and Fidra, in the Firth of Forth, were left as the only remaining purely catoptric lights in the service.A Standing Stone once stood on the highest point of the island.
Wikipedia https://en.wikipedia.org/wiki/Eilean_Musdile
Coordinates 56°27'26.623" N -5°36'15.234" E