One Tree Hill

U2 wrote this song about Greg Carroll, a Maori from New Zealand who became an assistant and close friend to Bono. Carroll was hired as local help when the group came to New Zealand in 1984 to kick off their The Unforgettable Fire tour. He endeared himself with his personality and work ethic, and was hired on full time (at Live Aid, he could be seen on stage handing Bono a microphone). Carroll was killed in Dublin on July 3, 1986 when he was hit by a car while running an errand for the band on Bono's motorcycle. The album The Joshua Tree, as well as this song, are dedicated to him.

One Tree Hill is the tallest of five volcanic islands in Auckland where Greg Carroll took Bono his first night in New Zealand. It is a tourist attraction in Auckland, with a monument at the summit dedicated to John Logan Campbell, one of Auckland's founding fathers. Bono shared his memory of the experience in the 2009 band biography, U2 By U2: "They took me up to the top of a place called One Tree Hill, where a single tree stands at the top of the mount, like some stark Japanese painting, and we looked around at this city that's made by craters of volcanoes. I remember it so vividly, I think, because it meant something to me about my own freedom."

In 1994, the One Tree Hill tree was the victim of a chainsaw attack by a Maori activist which almost ringbarked it. A further attack in 1999 all but finished the job and the life expectancy of the tree was estimated to be only three years. By October 2000, the pine had become unstable and was a danger to the public. After careful study of the condition of the tree, the decision was made to take it down. The felling operation was successfully carried out on October 26 amid much public attention, and the Auckland skyline was changed forever.