## 5 Discussion and Conclusions  
The right valley side of the Danube, especially in the area of Fruska Gora Mountain, is endangered by landslides. These landslides were observed during the first small-scale geological mapping. The first large facilities on the Danube, i.e., the Beska highway bridge, indicated the need for these landslides to be explored in much more detail as the bridge stability was endangered by soil displacement. At a later stage, other bridges were also built for which extensive geotechnical tests were performed, but despite that, many landslide-related problems have still remained unsolved. The landslide in the area of the Sloboda bridge in Novi Sad was investigated most thoroughly. Its stability and the possibility of the bridge structure collapsing due to landslides have necessitated the most accurate determination of the landslides' causes, the dimensions of the moving mass, geodetic and inclinometer measuring of the displacements, accurate definition of the groundwater status, design of remedial measures, and their execution in the current conditions. The most interesting landslide data were obtained by examining the drainage tunnel excavated through the body of the landslide. There were huge problems while excavating through the main sliding plane and the sliding zone, which are located on the borders of two large sliding blocks. Some large Danube landslides, such as the one in Cerevic, were repaired by digging deep drainage ditches from the Danube and upward to the slope and by forming an embankment of large crushed stone in the Danube riverbed. According to the project, the drainage should have drained the groundwater from the landslide as soon as possible in order to improve the resistant characteristics of the soil, and upstream of the stone embankment, a recent sand deposit would be formed, which would have a stabilizing effect on the landslides. Extensive geotechnical studies were also carried out in the Cortanovci area, including the excavation of 35 m deep investigation shafts. It was ultimately adopted to execute the most endangered zones of the Belgrade-Budapest high-speed railway on the bridge construction with deep piles, as repairing a landslide on a several-kilometer-long unstable slope would be very expensive. These examples of the construction of large structures have contributed to the detailed investigation of landslides in these places, whereas extremely large areas between them, with extremely large landslides as well, have not been investigated in such detail. The above examples have certainly contributed to the fact that much is known about the Danube-type landslides currently, but it is necessary to continue with thorough and comprehensive investigations. Extensive research of a relatively large area along the Danube has shown that landslides are active in areas where the Danube erodes the right valley side and where there are no alluvial sediments. Regarding that, it is certain that Pliocene clays and sand build the area starting from the Danube all the way to the loess sections on the slope in the landslide zones of Banostor, Cerevic, Bocke, and the Sloboda and Beska bridges. Many landslides are also evident on the sloped terrain in areas with wide alluvial plains along the Danube, such as Beocin, Sremski Karlovci, and Cortanovci. The influence of the Danube's erosion on them is significantly lower, and there are many elements to be further researched. According to some hypotheses, neotectonic activities, especially in the zone of Fruska Gora, contribute to the terrain instabilities and landslides along the Danube, which remains to be specified in future research. This was especially taken into account when investigating the landslide in the area of the Sloboda bridge, and the conclusion was that neotectonic activities at that location do not affect the process of sliding. The same conclusion applies to the pressurized water from the deep Pliocene sand, which is not affected by the landslide process.