Caithness. (You could theoretically swim from the Pentalina's pier to Stroma, but with the currents and the coldness of the water, I wouldn't recommend it!) Stroma was abandoned decades ago, and the infrastructure is apparently in a state of slow decay. Having looked at that picture (which is featured in the BBC article and can be viewed here), I think that the picture was probably taken somewhere around here. It's a neat island to pass by on the ferry, and if you the boat gets close enough you might see the Swilkie whirlpool. You can see some of the disused cottages as well. Stroma is the largest of several islands in the Pentland Firth, the others being the Pentland Skerries (the largest of these being Muckle Skerry, which hosts a lighthouse) and Swona, which was abandoned by its inhabitants in the 1970's and hosts a herd of feral cattle.
Foula, in Shetland. I've talked about Foula before, as I saw it from Sumburgh head, and then subsequently on the observation deck of the ferry while leaving Shetland. I had wondered if it was the Fair Isle, but subsequently learned that the Fair Isle was south, not west, of the main Shetland islands; and also, just over the horizon. Being that far from the main isles of Shetland, it's one of the most remote points in the United Kingdom. I love that photo, which was taken in the 1960's. It's right here. You can read more about Foula here and here. Unlike Stroma, Swona, or the Pentland Skerries, Foula is still sparsely populated. You can see more pictures of the Foula post office here, here and here.
Since the photos above aren't my own, I'll do the gentlemanly thing and cite them accordingly. Per Geograph, here's the citation for that phone box on Stroma:
Telephone box (disused), StromaAnd from Wikimedia, here's the one for Foula:
This telephone box dates from the 1960's when the last of the islanders left for pastures new. The track to the left of the telephone box goes down to the South Harbour.
© Copyright George Brown and licensed for reuse under this Creative Commons Licence.
"Foula post office" by Dr Julian Paren - geograph. Licensed under Creative Commons Attribution-Share Alike 2.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Foula_post_office.jpg#mediaviewer/File:Foula_post_office.jpgThese are the sorts of islands that one might be forgiven for considering settling on: remote, solitary, and beautiful. That said, they certainly have their drawbacks, among these being extreme isolation, a lack of fresh water, and the kind of wind that must be experienced to be believed.
I may try to post about a few more islands in the coming weeks, be they in Orkney or Shetland. Stay tuned.