The former railway bridge lies between Illerbeuren and Lautrach in the Unterallgäu region and is a testament to this rammed concrete construction method, which was replaced with the advent of reinforced concrete at the beginning of the 20th century. The structure was part of the 16.8-kilometer-long Memmingen–Legau railway line and was also the largest of seven bridges on the route.
The Iller Bridge owes its continued existence as a listed building to a Lautrach couple whose courageous actions at the end of World War II prevented it from being demolished by the Wehrmacht.
Since its closure in 1972, the railway line, popularly known as the "Legauer Bähnle," has been considered a visible symbol of structural change in the region. Due to increasing private transport, it became obsolete. In 1975, the German Federal Railway donated the bridge to the Unterallgäu district free of charge and the entire, dismantled railway line for a symbolic price. A cycling and hiking path from Lautrach to Illerbeuren was opened.