A disused magistrates' court was awarded a £4.6 million (€5.2 million) lottery grant to transform it into a maritime museum.
The Grade II listed building, which was used to reel criminals into the dock for decades, is being converted into Southampton Sea City Museum.
Situated in the heart of the Cultural Quarter, Sea City Museum will house two permanent galleries.
Gateway To The World will examine the city's role in the global context of emigration and immigration over 2,000 years, and Southampton's Titanic Story will recount "previously untold" stories of the 549 Southampton people who lost their lives on the ship in 1912.
There will also be space for temporary exhibitions.
The Heritage Lottery Fund cash will allow Southampton City Council to develop the project.
The building was designed in the 1930s and was empty since 2001, the HLF said.
Carole Souter, chief executive officer of HLF, said: "Southampton Sea City Museum will be an exciting addition to the city's cultural quarter and will remind people of its important contribution to the UK's maritime heritage.
"Heritage Lottery Fund money is helping Southampton's council create a place which tells the fascinating and moving stories surrounding Southampton's Dockyard."
Six projects received initial HLF backing which means they passed the first hurdle and will go on to compete for a firm award.
Funding was also awarded for them to develop their proposals further. These include: Britten 100, Aldeburgh, Suffolk - initial support for a £1.2 million HLF bid, including £65,800 development funding. Benjamin Britten, one of England's most famous composers, lived at the 17th-century Red House with his partner, the tenor Peter Pears, between 1956 and 1976. Increased exhibition space would open up the site to more visitors. The project is part of a programme leading up to the centenary of Britten's birth in 2013.
The proposals also include The Secret Meadows of Bury Farm, Hope-under-Dinmore, Herefordshire - initial support for a £1.06 million HLF bid, including £72,200 development funding.
Other proposals
• The Wessex Gallery, Salisbury - initial support for a £1.6 million HLF bid, including £87,400 development funding. Salisbury and South Wiltshire Museum plan to create a new gallery in Salisbury Museum to show the history and archaeology of the local area. It would house the museum's archaeological collections, including material from every 20th century excavation of Stonehenge, the Pitt Rivers Wessex Collection and the Amesbury Archer. Plans make up the first phase of a 10-year master plan to redevelop the museum.
• Portrait of Britain/British Film Institute, UK-wide - initial support for a £1.65 million HLF bid, including £40,000 development funding. The partnership project between national and regional film archives is designed to explore local community history through the evocative medium of film. It aims to give people online access to their heritage as represented on film and television, regardless of where they live or where the material is held. The project, including dedicated educational resources, training and mentoring, will be rolled out across.