AlHijjah 24, 1436, Oct 8, 2015, SPA-- Experts Thursday began post-disaster excavation surveys and rescue excavations at earthquake damaged U.N. Educational, Scientific and Cultural Organization (UNESCO) World Heritage Sites in the Kathmandu Valley in Nepal. "Creation of risk maps and identification and characterization of subsurface archaeology will facilitate the future protection, preservation and presentation of the Kathmandu Valley World Heritage Site, specifically, the severely damaged sites of Hanuman Dhoka, Patan and Bhaktapur," Christian Manhart, UNESCO representative to Nepal, said in a statement. The 7.8 magnitude quake that hit Nepal in April caused more than 8,000 fatalities and devastated large areas of county and neighboring regions, including destruction of Nepal's monuments within the UNESCO Kathmandu Valley World Heritage Site of Universal Outstanding Value. The experts will create archaeological risk maps within the three Darbar squares using ground penetrating radar, which will provide a detailed layout of archaeological features such as walls and buildings below the surface. This will be critical in guiding the laying of new service infrastructure, protecting key elements of Kathmandu's underground heritage for future generations, UNESCO said.