The definition of a crannog has to be “artificial island, usually built in lakes, rivers and estuarine waters”. They have been variously interpreted as free-standing wooden structures, as at Loch Tay. The word “crannog” is from Old Irish and means young tree.
They were made to protect the more wealthy families of a population. Scotland has now 400 crannogs, but Ireland still holds the record with over a thousand of them. Besides being used by wealthy families, the crannogs have also served as non residential hunting and fishing stations, and holiday homes.
Now they have reconstructed a crannog on Loch Tay in Scotland, and it’s open to visitors everyday day from Easter to October. A team of archaeologists from Edinburgh University has given us a good picture of how the people lived in crannogs, so you can learn a lot by visiting it.
Speaking of floating residents, here you have the floating island of Lake Titicaca where people actually live.