The ancient Celts tended to build their forts and cities in areas that offered natural protection. Yet, when nature was unable to protect them the Celts were more than capable of helping themselves. The tribes of Britain and Ireland constructed artificial islands known as ‘crannogs’ in rivers and lakes. Crannogs varied in complexity from mounds of peat and brush to structures with boulder foundations supporting wooden pile and beam platforms that sat just above the water level. Some even had early drawbridges that could be raised in the case of a sudden attack.
