## 4 Discussion
### Surveys: Validation and Archaeological Site Significance  
Building on recent advances in digital image analysis and feature detection, we developed an RF algorithm that allows the automated detection of these types of enclosures in Pleiades images with high resolution and Sentinel-1 for better archaeological detection. We also used SAR images to increase the accuracy of classification, which provided good results. In addition, we only used the Google Earth Engine for the view, so we cannot use it for building a machine learning detection model. We successfully used the RF model to detect new sites in satellite imagery. The model detected these sites, which we verified and confirmed in the field. We built the training dataset using both Pleiades and Sentinel-1 images in the Google Earth Engine. Of course, the identification of any object or location as archaeological remains based on images requires confirmation from the ground. The discovered sites described above were confirmed in the area of Blad Talh in southernTunisia by machine learning, remote sensing data, and field investigation. Other than the surrounding wall and the ruins of the fortified sites, no other archaeological ruins were seen above ground. Almost all the visual features in the analysed RF results were determined to be micro-topographical results of archaeological importance. As a result, our approach reveals a different layout of archaeological sites, and the algorithms identified structures in the area very well. In November 2021, the exploration team arrived at sites approximately 10 km north of the suspected location of the ancient Roman fortification, KSAR GRAOUECH (a square-shaped mark). Each side of the suspected location was measured to be around 50 m long. These anomalies have no intact walls, but the remains of some wall piers were investigated to identify anomalies. Shards of ancient ceramics were scattered among the walls, and their environs date back to the Roman period, as shown in Figure 6G,I,N,L. Buried walls at these five fortified sites were also unearthed, representing the appearance of concealed remains, as shown in Figure 6C,F,H,J,M. The field investigation conducted in this region reveals the existence of a farm dating back between the Roman Empire and Byzantine times based on the discovery of tiles and shards of ancient ceramics from the Roman period. These fortified sites are situated between Capsa (Gafsa) and the coastal towns of Iunci and Lariscus. Controlling one of the passes to the north would have been of obvious strategic importance during the Roman era, a consideration that strongly supports their inclusion in the list of official fortifications of that period. In addition, these sites have common topographical and archaeological features, and their dimensions are relatively similar to each other. According to [PERSON] [74], these fortified sites are widely spread in the rear Limes area and are located on the immediate edge of a Roman road or in a control location of a passage; some have been identified as military works that are a part of the defensive system. In the report by [PERSON] et al. [75], these were probably fortified farms that adopted a plan inspired by the military project. The parallels between military architecture and these fortified sites, namely Mattingly Qsur, are very evident in the adoption of the rectangular form with towers projecting from two or four facades [76]. The results of studies investigating this type of site in Fazzan and Cyrenaica in eastern and western Libya, respectively, confirm that the peak occupation of fortified sites occurred after the end of the third century and continued in some regions in later times. More specifically, the majority were occupied between the 4 th and 6 th centuries (350-540 AD) [77]. Indeed, the general landscape of the Blad Talh was a highly important part of the ancient Roman period.