## 1 Introduction  
Landslides along the Danube, on the territory of Vojvodina (Serbia), occurred on the northern slopes of Fruska Gora Mountain. Fruska Gora is a low mountain in the Pannonia Plain. It is of elongated shape, with a length of approximately 40 km and a width of about 15 km. Its genesis is related to tectonic activities in the earth's crust and the rise of its central area over relatively long faults. Fruska Gora is a host-type mountain, and its large part has been declared a national park. Some researchers [1] hypothesized that the rise of fault blocks directly affects the activation of sliding processes. The whole area of Fruska Gora is intersected by streams. Its entire periphery is surrounded by smaller and larger settlements, including the city of Novi Sad. Landslides endanger significant infrastructural facilities, constraining the expansion of populated areas or endangering the stability of individually built structures. The most interesting thing about this is the Bocke landslide, with about 1000 vacation homes declared a part of Novi Sad in the previous period. There are a number of landslides formed on Fruska Gora, particularly on its northern slopes, which are generally inclined toward the Danube River [2; 3]. A more detailed exploration of these landslides began in the middle of the last century. This was the time when the construction of railways and roads intensified, in some places, on the landslides.  
The current level of landslide exploration enables us to classify them into two major groups: deep and shallow landslides. In this study, landslides near the Danube are analyzed in a manner similar to the studies performed in the literature [4; 5; 6; 7; 8; 9; 10]. Deep landslides are those situated along the river, afflicting a large area that is difficult to repair. They are typically more than 20 m deep. Landslides are usually named after the closest settlement, for example, Beska, Bocke, Sremska Kamenica, Sremski Karlovci, Cortanovich, etc. Thispaper points out the fact that these are unstable slopes extending several kilometers in length along the Danube area. These unstable slopes consist of a great number of smaller but deep landslides. Their displacements vary in time as well as in amount and direction [11]. Figure 1 shows the locations of the largest unstable slopes along the Danube in Vojvodina.  
The number of shallow landslides is particularly high in the surface zone of the terrain on slopes with deep landslides. Shallow landslides are stressed around the perimeter of unstable slopes, indicating the expansion of the sliding process along the slope. Upon the reparation of these shallow landslides, displacements will continue along the deep sliding planes.  
This paper presents the results of landslide investigations in a relatively large area conducted over a long period of time. That is why some landslides, particularly those in the zone of large bridges on the Danube, were examined in great detail, while many others were investigated superficially, that is, only in the form of mapping. The most detailed investigations were started in the area of the Beska bridge on the Belgrade-Novi Sad highway when significant deformities were observed on the bridge caused by the landslide displacement, which endangered the stability of the bridge. In addition, detailed tests were performed on other landslides mentioned in the paper, which included exploratory drilling, inclinometer measurements of landslide displacements, geodetic measurements of landslide displacement, detailed hydrogeological investigations of landslides, geotechnical investigations of landslides in the phase of designing remediation measures, and laboratory geomechanical tests.