The old international airport of Gaza was once able to handle 700,000 passengers per year and operated 24 hours and 364 days a year, closing only on Yom Kippur. The $86 million airport opened its doors in 1998, but it closed in 2001 after being severely damaged by Israeli military forces. Now hundreds of Palestinians have taken over the old landing strip of the airport, digging up the tarmac, taking away truckloads of stones to sell as construction material. Under Israel's siege only limited amounts of construction materials are allowed in for United Nations projects. So there's a booming black-market. Four years ago a tonne of sand sold for 60 dollars - now it's 600.