Over a period of more than 150 years (the 1st. century BC - the 1st. century AD) Dacia disposed of a genuine defense system, containing more than 90 defense works, of various types: fortified settlements, fortresses and earth works. As for the defense works of pre-Roman Dacia, those from the southwestern area of the nowadays Transylvania represent a particular group. Built in the southern side of the middle basin of the Mures river - in that part of the Meridional Carpathians that form the Sureanu Massif - they permitted a continuous control of the ways of access to the capital city of the Dacian kingdom, Sarmizegetusa. [...] In this area of the capital city of the Dacian kingdom, the vestiges of the Dacian dwelling make up a unique ensemble, in which the elements of the autohtonic civilisation mould extremely well with those that have been borrowed from the Greco-Roman classical world.The archaeological excavations effectuated at Sarmizegetusa - which is situated on the western side of the Sureanu Mountain - revealed rural Dacian dwellings in the vicinity of the quasi-urban ones, proving a preoccupation for the urban and the territorial arrangement, as well as the existence of some economical functioning that belong to the similar centres (Fetele Albe, Ceata, Sarmizegetusa - Grãdiºtea de Munte); on this occasion there were discovered defence works proper that had been set on fire by the Romans, on the occasion of their victory, obtained by Trajan in 106, which thus concluded the second military campaign against the Dacian King, Decebalus. The defence works proper can be divided into three categories: fortresses that were built in the proximity of the civilian centres (Costesti-Cetatuie, Vârful lui Hulpe and Sarmizegetusa - the latter two on the area of the present - day locality of Gradistea de Munte) fortresses that do not have civilian centres around them - they have been built strictly from military reasons (Costesti - Blidaru, Luncani - Piatra Rosie) and the imposing defence wall from Cioclovina-Ponorici. This one is built of wood and unshaped stones; it is more than 2,5 km. long and it has immense bulwarks of 40 to 80 meters in diameter, as well as oblique and perpendicular walls which are to the main wall and have the role of braking up the enemy's front of attack. The whole wall reveals the traditional Dacian technique, but the bulwarks and the perpendicular walls betray elements that have been borrowed from the Hellenistic world.

In the case of the fortresses, the plans are either traditional (but adapted as much as possible to the configuration of the land, without significant adjustments), or Hellenistic architecture. The category of the fortresses with traditional plans include the defense works made of wood and earth, at Costesti-Cetatuie, as well as those of earth, wood and stone, at Sarmizegetusa. The fortresses with plans inspired by the Hellenistic architecture include the defense works from Costesti-Blidaru and Luncani-Piatra Rosie. The same observation can be made for the defense works, as well: walls of stone shaped in Hellenistic manner (at Costesti-Cetatuie and, partly, at Costesti-Blidaru) and walls of shaped stone, inspired by the Hellenistic technique (partly, at Costesti-Blidaru and at Luncani - Piatra Rosie and Sarmizegetusa). All together, these defence works constitute a defensive system for Sarmizegetusa, but taken separately, each of them represent, through their specific features, a well configured entity. There is, however, a generally valid characteristic: the fortresses can not resist to prolonged sieges due to the fact that the permanent source of water is lower than the height of the defence work [...]. The oldest defence work is that of Costesti-Cetatuie, and it was built on the brink of the 2nd century AD when, on a 150 meters high knoll, two ground elevations with a multiple stockade on their tops, were arranged. [...] It is probable that, around the year 55 BC, after the conquest of the Greek fortresses from the western shore of the Black Sea, by the Dacian King Burebista, the native craftsmen and the builders contributed to the raising of the wall (4 meters thick), of shaped stone, on an angular tract. It was provided with three bulwarks - excepting the one that was situated in the precincts, on one of the ground elevations, as well as other three bulwarks from outside the defence work, situated on the way of access, as well as two other inhabitable towers. All these elements of defence are built with Hellenistic walls, with filling of the emplecton type (earth and river stones, placed between two walls of shaped stone). The way they look and other elements as well, lead us to the idea of the contribution of the Greek craftsmen: it is the case of the inhabitable towers (their first levels are built of walls of the same type, while the storeys are made of slightly burned bricks), the case of the monumental stone stairs, near the western inhabitable tower; it is also the case of the on a segment of the precincts wall. Inside the fortress there is also a watch tower, a tank for rain water, huts for soldiers and a rectangular sanctuary with wooden pillars and shaped stones pedestals; other three rectangular sanctuaries, which were built with the same technique, are outside the walls. At the base of the knoll (under the present-day locality) there stretched the big civilian settlement.