The Pictish hill fort was a common sight in the parts of modern day Scotland that were never integrated by the Roman Empire. Made of a series of earth embankments often faced in wood and rarely stone, Hill forts were an imposing sight. They followed the natural incline of the hill wherever possible, and where this was not possible trenches were dug in front of the segment of wall and the dirt removed was used to form the wall. The embankments could be anywhere from 2-4 meters in hight, but the wooden areas averaged 3 meters. Often times villages would spring up inside the forts, fully self sufficient and with farms and animals, this was because of the protection offered from other tribes, wildlife such as wolves, and invading Romans.

One noteable example of an early hill fort was "Maiden Castle", in modern day Dorset. Follow the link for more information. http://www.english-heritage.org.uk/daysout/properties/maiden-castle/?utm_source=maidencastle&utm_medium=redirect&utm_campaign=redirect