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Damage occurred to a broadcasting tower and ancillary buildings at the top of a hill close to Valcava, Lombardy, due to slope instability at a limestone quarry in operation on the other side of the hill . A landslide occurred in the pit after two days of rains, and cracks began to appear in the building parallel to the slope face. Detailed geological and geotechnical surveys were carried out and numerical analyses performed to identify the main causes of instability and to suggest an adequate stabilisation system. Two main natural causes were identified: the complex geology of the site (two faults, a boundary between two limestone facies, down-slope dipping bedding planes and two sub-vertical sets of discontinuities) and the hydraulic condition of the site after prolonged rainfall. Excavation of the pit area released confining stresses in the bedding planes, inducing a sliding movement; instability from quarrying was progressively propagating upslope towards the foundations of the broadcasting facility. Stabilisation could be carried out by: limiting hydraulic pressure in the slope by sealing cracks, installing sub-horizontal drains, channelling of water runoff, isolating the broadcasting site from the unstable slope, and discontinuing quarrying towards the facility., Damage occurred to a broadcasting tower and ancillary buildings at the top of a hill close to Valcava, Lombardy, due to slope instability at a limestone quarry in operation on the other side of the hill . A landslide occurred in the pit after two days of rains, and cracks began to appear in the building parallel to the slope face. Detailed geological and geotechnical surveys were carried out and numerical analyses performed to identify the main causes of instability and to suggest an adequate stabilisation system. Two main natural causes were identified: the complex geology of the site (two faults, a boundary between two limestone facies, down-slope dipping bedding planes and two sub-vertical sets of discontinuities) and the hydraulic condition of the site after prolonged rainfall. Excavation of the pit area released confining stresses in the bedding planes, inducing a sliding movement; instability from quarrying was progressively propagating upslope towards the foundations of the broadcasting facility. Stabilisation could be carried out by: limiting hydraulic pressure in the slope by sealing cracks, installing sub-horizontal drains, channelling of water runoff, isolating the broadcasting site from the unstable slope, and discontinuing quarrying towards the facility.