The "Tree of Life" was created from weapons collected as part of a project in Mozambique which exchanges guns for building materials and other equipment.
In nine years the project has collected and dismantled more than 600,000 weapons left over from the civil war.
The British Museum and Christian Aid commissioned the piece for the start of the arts festival Africa 2005.
The artists used AK-47s, pistols and rocket-propelled grenade launchers to create the piece of art which they see as a way of promoting peace.
There are still millions of arms hidden throughout Mozambique, a legacy of the 16-year-long civil war that ended in 1992.
Artists in Mozambique created the 'tree of Life'
The Transforming Arms into Tools project has been so successful in collecting guns from former soldiers that other African governments are considering implementing similar schemes.
Bishop Dom Dinis Sengulane, founder of Transforming Arms into Tools, said: "I tell people that sleeping with a gun in your bedroom is like sleeping with a snake - one day it will turn round and bite you."
Dr Daleep Mukarji, director of Christian Aid, said: "It's amazing to see how Mozambican artists build a culture of peace through creating fascinating sculptures from dismantled killing machines.
"This project encourages people to exchange tools of death with tools for living."
Neil MacGregor, director of the British Museum, said: "It is an extraordinary, thought-provoking sculpture which is a potent emblem of the complexities linking Africa to the rest of the world."
See BBC NEWS | Museum to unveil gun sculpture