Former South African president and Nobel Peace prize laureate F W de Klerk imprints his feet at the Maropeng Cradle of Humankind World Heritage site in Krugersdorp. The Maropeng Cradle of Humankind World Heritage site has been working on a strategy to collect footprints of Nobel Prize laureates and state presidents since 2002, when former South African president Thabo Mbeki and former UN secretary-general Kofi Annan initiated the tradition.