The bivallate hillfort is protected on the south and east by two parallel ramparts and an unusual type of inturned entrance 11 yards (10 m) wide. There were three phases of hillfort construction at Helsby. The first stone rampart was constructed in the middle to late Bronze Age (1250-1050 cal BC) and consisted of a bank of well dressed, outer face of sandstone blocks and an irregular inner face, which was built on a slight batter; it was approximately 4 yards (3.5m) wide. A socketed bronze axe found at Helsby in 1925. This was followed by a series of colluvial deposits against the internal face of the stone rampart that formed the second phase of activity. The third and final phase was the re-building of the rampart in the post-Roman period, dating as late as 530 AD suggesting early Saxon re-occupation of the hillfort.