Background The Szachownica cave is one of the longest cave systems in the Jura Krakowsko-Wieluńska (southern Poland). It is the country’s second largest hibernation site for bats, with more than 2 000 bats of 10 different species hibernating there every year. These include four species listed in Annex II of the Habitats Directive: Barbastelle (Barbastella barbastellus), Bechstein's bat (Myotis bechsteinii), the pond bat (Myotis dasycneme) and the greater mouse-eared bat (Myotis myotis). Other bat species at the site are: Serotine bat, Brandt’s bat, Daubenton’s bat, whiskered bat, Natterer’s bat and the brown long-eared bat. Human intrusion into the rock formation has disturbed the massif equilibrium. Very intense processes of disintegration of geotectonic structure are intensified by natural processes of frost cracking and karst phenomena. Furthermore, some recent rock slides and ceiling deflection have occurred in the artificial halls. It is also thought that a partial cave collapse is inevitable and would result in loss of hibernation space and decreased bat swarms. Objectives The project’s overall objective is to provide proper protection of the habitats of the bat populations of the Szachownica cave, a Natura 2000 network site. Specifically, the project aims to stop the breakdown of the roof of the cave and provide optimal conditions for the bats that hibernate there. In order to stop the disintegration of the cave, conservation work must include maintenance and ceiling reinforcement. The work will be carried out in two interlinked stages: Stage I – Temporary ceiling reinforcement, using timber props to prevent the collapse of the most unsafe parts until permanent reinforcement is ready for installation. When the maintenance is finished, the props will be removed and the cave returned to its natural shape; and Stage II – Final ceiling reinforcement through a combination of i) a reinforcing-sealing injection into the cave roof i.e., this involves squeezing a bonding agent into holes drilled into the roof. Polyurethane resins will be used as an injection agent. The agent is also a filler providing good binding for any cracks; and ii) reinforcing the rock formation with anchor plates (poles) on the surface by using ground anchor plates. During binding, a gluing agent will boost its volume, penetrate slots and bond the cracked rocks. This anchoring system will also be used to stabilise the excavation, with the anchor plates taking on the tensile stress in the cave ceiling. Precise analysis of the cave will allow the project team to determine the required number of anchors and injection holes, as well as their location and length, thereby ensuring the long-term preservation of the cave. Expected results: The project expects to achieve the following results: Make permanently safe 1 000 m2 of the rock roof in the Szachownica cave; Make permanently safe other parts of the rock roof and side walls; Maintain the existing number of chambers and their structures, as favoured by the bat populations; Maintain the current shape of the cave entrance; and Ensure the proper ventilation of the cave.