Kathmandu (AFP) - Reduced to piles of rubble and splintered wood, Nepal's rich cultural heritage has suffered a devastating blow from a massive earthquake that tore through the country, experts said Sunday.In the heart of Kathmandu, many of a cluster of temples and statues built between the 12th and 18th centuries by the ancient kings of Nepal have collapsed, killing scores and trapping others underneath.The nine-storey Dharahara tower, a major tourist attraction in the city's Durbar square with its spiral staircase of 200 steps, was reduced to just its base when the 7.8-magnitude quake struck at lunchtime on Saturday."I had just bought tickets to climb the tower and was at its base when I felt a sudden shaking," Dharmu Subedi, 36, said from a hospital bed in Kathmandu. "Within minutes, the Dharahara had crumbled to the ground with maybe more than 100 people in it," Subedi told AFP.UNESCO was trying to gather information on the extent of the destruction, including at three palace-filled squares in the cities of Patan and Bhaktapur, both former kingdoms in the Kathmandu Valley, as well as in Kathmandu."We understand the historic Durbar squares of Kathmandu, Patan and Bhaktapur have been badly damaged," Christian Manhart, UNESCO's representative to Nepal, told AFP."Several temples have collapsed.