In 1987, BCEE launched a plan to extend the former casemate, so that it would connect the bank's four buildings that lie on the plateau.[2] The possible usage of the tunnel itself was debated, and the idea was formed to turn the tunnel into a gallery. Construction began in 1992, and the gallery was opened in 1993.[3] It is primarily dedicated to hosting works by more than a hundred Luxembourgian artists, particularly the photographer Edward Steichen, to whom a permanent collection is dedicated. However, the gallery also hosts retrospectives of other artists.[2]