IT will be the largest development in Southampton which will terminate a half century of the world's most famous mapping agency on the site.
In its heyday more than 5,000 people, most from the local community, worked for Ordnance Survey at its headquarters in Maybush.
Now, with the major city employer is moving to pastures new, the Daily Echo can reveal what the future may hold for its sprawling 25-acre site in Romsey Road.
A £200m scheme has been finalised to go before planners.
Ordnance Survey has been based in Romsey Road since 1969, but says its ageing premises are too costly to maintain. OS is in need of extensive modernisation.
Rather than selling the land, valued at more than £20m, it instructed London based Kier Property to come up with a mixed development
It will be anchored by 465 new homes, including 328 flats and 137 houses.
The development will feature a new 30,000 square foot business enterprise centre which will be home to up to 20 business start-ups.
Compass House, which is home to HM Revenue and Customs' offices, will be refurbished and have another storey added for business use.
A new 80,000 sq foot warehouse for light industrial use is also planned which could retain the OS print operation.
A row of shops, a doctors and veterinary surgery, and 80-bed residential nursery home are also included in the plans. The development will create about 1,200 jobs.
Kier commercial director Nigel Turner said it was important to retain some employment opportunities.
He said: "There are better employment sites but we stepped back from having all housing to create a mixed development. We think it's a good compromise."
He said trees had been retained on the western part of the site while the eastern part attempted to replicate the existing tall office buildings, set to be demolished.
The plans have been submitted to Southampton City Council for outline planning permission.
Nearby ward councillor Don Thomas said: "The biggest part of my case work is people looking for somewhere to live. If this helps by putting homes within their grasp then I welcome it."
He added: "It's always sad when a business moves on, especially when it was such a big part of the community."
Nearby shops said they feared the new proposals would lead to a loss in trade and bring more traffic.
Work is unlikely to start on the Romsey Road site until Ordnance Survey has moved into its new three-storey £45m corporate headquarters at Adanac Park, about a mile away alongside the M271. About 1,000 workers will make the move.
Ordnance Survey has been based in the Southampton area since 1841 when it moved here from its first home in the Tower of London. Until the 1960s, staff worked at an office in the city's London Road before the switch to Romsey Road.
An OS spokesman said: "Romsey Road is a substantial development site with possibilities for new business and employment initiatives alongside new housing. It is not a viable option for us to redevelop the site for a new head office.
"Moving to Adanac Park is a far better option because it is financially more sensible, it avoids the disruption of a phased demolition of the current building while remaining on site, and it offers us the chance to achieve ideal, purpose-built accommodation in line with modern working practices."
Comments on the Romsey Road plans can be made to Southampton City Council quoting ref: 07/01700/OUT.