13-year-old American boy is to bid to climb Mount Everest. He has modest ambitions – pick a small piece of rock from the top of the world as a memento and wear it in a necklace. <br/><br/>Jordan Romero from California, currently in Kathmandu, is due to leave for the mountain tomorrow. If he succeeds, Romero will become the youngest climber to scale the 8,850 metre Everest summit. Currently, a 16-year-old Nepali boy, Temba Tsheri Sherpa, holds the record of being the world's youngest climber of Mount Everest. <br/><br/>Romero has already climbed Mount Kilimanjaro in Africa and Mount McKinley in Alaska, among others. More than 4,000 climbers have reached the top of Mount Everest since it was first climbed by New Zealander Sir Edmund Hillary and Nepal's Tenzing Norgay Sherpa in 1953.