Bagnoli was one of the sites of Naples' industrialization in the early 20th century, with the construction of a steel mill. During World War II Bagnoli was damaged as a result of the bombings of Naples.

After World War II, Bagnoli was overbuilt by virtually uncontrolled construction and then suffered urban decay. The first decade of the 21st century saw the removal of the steel mill and some improvement in the physical and visual landscape of the area, including the construction of a public educational facility and convention center called Città della Scienza (Science City) as well as the conversion of the long ex-steel-mill industrial pier to a public promenade.