The feature was photographed from the air by the Third German Antarctic Expedition (1938-1939), led by Captain Alfred Ritscher, but was not correctly shown on the maps by the expedition. It was mapped in detail by Norwegian cartographers from surveys and air photos by the Norwegian-British-Swedish Antarctic Expedition (1949-1952), led by John Schjelderup Giæver. It was remapped by air photos taken by the Sixth Norwegian Antarctic Expedition (1958-1959). They named it Borgmassivet (the castle massif) in association with Borg Mountain, its most prominent feature.