BETHLEHEM, Palestinian Territories: It was hidden for decades at the church on the site where Jesus Christ is believed to have been born until conservationists uncovered it — an ancient mosaic of an angel. Since 2013, Italian restorationists have been working with the Palestinian government in a mammoth effort to restore the Church of the Nativity in Bethlehem in the occupied West Bank — hailed by Christians as built on the site where Jesus was born. The roof and windows have been restored and mosaics that had become barely visible over centuries have been painstakingly brought back to full color, one tiny tile at a time. In the course of the work they were surprised to uncover an angel that had been hidden under plaster for decades. With thermal cameras, similar to those used by the military at night, they scanned the walls to see if there was anything behind them, said Giammarco Piacenti, CEO of the Piacenti restoration company which is leading the work.