Thanks, Mike, but no - Eilann Rann is a genuine island and much, much larger than a crannog, all of which were man-made. I think crannogs usually had space for 1-5 small dwellings and were 20-25m in diameter. We have an excellent example at our end of Loch Tay - it's now heavily treed which it wouldn't have been originally, and the smaller groups of scrubby trees show the line of the "secret", underwater causeway which was used to get to and from the actual crannog.