Engineers in northern Greece on Thursday began a costly operation to move a 12th-century Byzantine monastery that occupies land earmarked for a hydroelectric dam, an AFP photographer said.The state-run Public Power Corporation is spending 850,000 euros ($1.2 million) on the project near the city of Grevena to drag the 260-tonne building to higher ground before an artificial lake floods the area.Sliding on a 50-tonne tracked platform equipped with hydraulic pistons, the monastery is to be moved some 120 metres (400 feet) from its current location including 27 metres (88 feet) uphill, according to organisers. \"It is not the first time that this technique is applied,\" said engineer Dimitris Korres. \"With good weather conditions the building could move up to 30 metres per day.\" The uninhabited stone monastery dedicated to the Holy Virgin of Tornikio contains valuable murals dated to the 15th and 18th centuries. It was badly damaged in a 1995 earthquake but underwent repairs a decade ago. The Ilarion hydroelectric project is expected to generate 413 gigawatt hours (GWh) annually and meet the water supply and irrigation needs of Thessaloniki and outlying agricultural areas.