Isle of Man Guide

Around this time the Isle of Man saw the arrival of Celtic people from across the Irish Sea. These people brought with them the knowledge of working with iron. It was during the Iron Age that the island prepared itself against invasion. Large hill forts appeared on summits and smaller promontory forts were built along the coastal cliffs. The people of this time were not just advancing with their fortifications. During the more peaceful times (perhaps during the occupation of Britain by the Romans), the people began building roundhouses. These large timber structures had low roofs and central hearths. A chieftain, his family, household and animals all lived together under one roof. Later homes of this type were even built partly with stone. The sites of Balladoole and Cronk ny Merriu have the remains from the Iron Age.

Celtic Iron Age on the Isle of Man 500 BC - 500 AD
As stated in the Manx Museum