Caisteal Chiosmail (Kistmul Castle)

Caisteal Chiosmail is a small, rocky islet off the coast of Na h-Eileanan Siar in the Outer Hebrides. Its Gaelic name hints at a former fortified spot, though any masonry is scant; the feature is best known today for its exposed geology, nesting seabirds and the dramatic coastal views it provides rather than for permanent settlement.

Locally it figures in the maritime landscape of crofting and fishing communities and is often appreciated from shoreline walks or boat trips. Its interest is therefore as much cultural and historic - reflecting Gaelic and Norse place‑names and seafaring traditions - as it is ecological, contributing to the island chain’s wildlife and sense of place.