20 years after the Ban Mine Treaty, 23-year-old Srey Yen of The HALO Trust is clearing mines in Cambodia from a war she never knew. HALO has been operational in Cambodia since 1991. Since then, more than 50% of minefields have been cleared. In 1997, the International Campaign to Ban Landmines was awarded the Nobel Peace Prize and the international trade in landmines has ended.