These six fortresses were built in the course of two centuries (from 1st century before Christ to 1st century after Christ.) They were the nucleus of the Dacian Kingdom until the beginning of 2nd century. when they were conquered by the Romans. The fortresses show an unusual fusion of different cultural and technical influences between the classical world and the late European Iron Age. Their extensive and well-preserved remains stand in spectacular natural surroundings and give a dramatic picture of a vigorous and innovative civilization.