The U.S. estimates that 10 percent of the 80 million tons of munitions used by the U.S army in Vietnam failed to detonate on impact.
It's now up to the "landmine girls" to detonate them.
Libby Hogan reports.
Vietnam's "landmine girls" on mission to clear old bombs
Armed with a metal detector, Nguyen Thi Ha Lan walks slowly and carefully over unexplored empty fields in north central Vietnam's Quang Tri province.
A ping, then whirr of the detector tells her something is hidden below.
Digging up sand - she finds a cluster bomb.
A warning is made to tell people to keep back before an earthshattering boom.
Lan is part of an all-women explosive disposal team working to rehabilitiate over 60,000 hectares of farmland pitted with bombs left behind from the war with the United States that ended in 1975.
(SOUNDBITE) (Vietnamese) MEDICAL OFFICER OF EXPLOSIVE ORDNANCE DISPOSAL TEAM, NGUYEN THI HA LAN, SAYING: "It is an honour to wear the uniform of the project everyday, so even if we aren't able to wear make up or a beautiful dress like everyone else, we all feel proud from the bottom of our hearts." In Quang Tri alone, there have been over 8,500 casualties from accidents involving unexploded bombs.
Around 30 percent of the victims are children who mistake the round-tennis ball sized cluster bombs as a rock to play with.
For Lan, being part of the 16-member team has a special meaning.
At the age of 12, her mother Hoa lost both legs and an arm due to an unexploded ordnance.
(SOUNDBITE) (Vietnamese) MEDICAL OFFICER OF EXPLOSIVE ORDNANCE DISPOSAL TEAM, NGUYEN THI HA LAN, SAYING: "When I look at the kids playing in my front yard, it reminds me of my mother and I used to cry silently inside.
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.My job now enables me to have a stable life and the kids are able to play around me on Quang Tri soil and all over Vietnam too.
Demining is gruelling and dangerous work.
Teams such as Lan's have helped clear unexploded ordnance from around 14,000 acres of land.
The land has been handed over for development and agricultural expansion.
Lan says working in an all-women team brings out a powerful camaraderie.
The demining force hopes to rid the province completely of unexploded ordnance by 2025.