The Blue Nile basin is severely affected by slope failures. The characteristics of its deep gorgesrnand rugged valley walls composed of assortment of different geological materials makes the arearnlegitimate for study. The stretch of main road 3 that passes through the Abay Gorge steeplyrnclimbs nearly 1,500 meters from the ïbay River to the plateau in 40 kilometer distance. It isrnplagued by landslides in the rainy season, especially from June to September, Some of the failurernareas are up to two kilometers wide, putting into jeopardy this vital link road. rn rnWork was commenced with the conception of site reconnaissance and the study area in particularrnprovides long cliffs of sandstone, limestone, and gypsum intercalated with relatively soft units ofrnmudstone, shale, and marl. From satellite view also the surface anomalies of the five selectedrnpriority sites shows multi block land slide mass in each station. rn rnInterpretation and analysis of detailed borehole investigation data and different monitoringrndevices output data is carried out in order to grasp movements and to find the main slip surfacernand the geological structure. Using inverse analysis for the representative landslide blocks thernshear strength parameters of the most probable slip surfaces were determined. rn rnFinally, the study led to the conclusion that the landslides are triggered by rising ground water inrnthe rainy season. The rising of ground water table is due to infiltration of surface run off.rnTherefore, controlling of the infiltration process using different remedial techniques willrnminimize the sub surface problem