Bowie stated on several occasions that the song was based on the time he "saw two lovers standing by the Berlin Wall. An East German watch tower stood high above them, manned by armed guards." He told Rolling Stone Magazine: "Why did they choose the gun turret? I assumed their motive was guilt, thus the act of heroism in facing it." He also told a U.S. reporter: "Maybe they felt guilty about their affair and were drawn to the spot for that reason, to cause the affair to be an act of heroism. It seemed a very 70's incident and their personal survival by self-rule--that's my only positive thought on society today."
HOWEVER, there are two other accounts to this story:
1.) Tony Visconti, who co-produced "Heroes" and was a back-up singer on the album, claims that Bowie saw him and Antonia Maass, a back-up singer on the album, holding hands and kissing near The Wall. In fact, only a small section of The Wall was visible from the recording studio; and Tony and Antonia had passed by this section. When they returned to the studio, Coco (??) said to Tony: "We saw you walking by The Wall and that's where he got that idea from."
2.) While in Berlin, Bowie had visited the Brücke-Museum on several occasions, and three paintings in the museum inspired Bowie's visual work during this time period. One of Bowie's favorite artists whose works were on exhibit at the museum was Otto Mueller. One of Mueller's pictures, painted in 1916, was Lovers Between Garden Walls. This painting portrays two lovers next to a wall and is likely the source of Bowie's inspiration for "Heroes."
The other two paintings, Gramatte's self-portait inspired the "Heroes" album cover; and Heckel's Roquairol inspired Iggy Pop's 'The Idiot' album
cover, which was released on March 18, 1977. Bowie co-produced the album and co-wrote 8 songs.