The archaeological evidence is more reliable in respect of the Iron Age. Traditionally, it had been supposed that the tribes of central Scotland had made little or no use of the Castle Rock. Excavations at nearby Dunsapie Hill, Duddingston, Inveresk and Traprain Law had revealed relatively large settlements and it was supposed that these sites had been chosen in preference to the Castle Rock. However, the excavation in the 1990s pointed to the probable existence of an enclosed hill fort on the rock, although only the fringes of the site were excavated. House fragments revealed were similar to Iron Age dwellings previously found in Northumbria.