The D-Day Map Room / / No Comments The Map Room at Southwick House in Portsmouth was where Allied Supreme Commander General Eisenhower and General Montgomery spent much of early 1944 planning for D-Day. The walls of the Map Room were hung with huge maps of the English Channel. Maps that are still in place in the Map Room at Southwick House to this day.In particular one wall of the Map Room is covered by a very large map of Maps Mania… more → Posted in: Interactive Maps Tagged with: DDay, Room