Shetland, also known as the Shetland Islands, was an archipelago of Scotland. (TV: Let's Kill Hitler) It was located far off the north-east coast of the Scottish mainland, north-east of the Orkney Islands. (TV: The Lie of the Land)
According to the Eleventh Doctor, "not even a Shetland" of Scotland had ever been conquered. (TV: Let's Kill Hitler)
In 1997, a Jathaa sunglider fell to Earth off the Shetland Islands having been shot down by the Torchwood Institute. (TV: Army of Ghosts)