Smaller Welsh museums will also benefit, promises Eurwyn Wiliam, the deputy director general of NMW, which is celebrating its centenary this year. 'One of the downsides of devolution is that we have found ourselves cut off from previous funding streams,' he says. 'But it has also meant that we are working together under a better structure to enhance museums and galleries across the country, creating new partnerships and dialogues that were not in place before.'
NMW, which has seven museums in total, has emerged from a lengthy strategy review with three revitalised museums: the National Slate Museum in Llanberis, north Wales; the National Wool Museum in Aberystwyth, west Wales; and the Big Pit National Coal Museum in Blaenafon, south Wales, which won the Gulbenkian Prize in 2005.
Swansea's National Waterfront Museum, built at a cost of £34m, has also proved a great success since opening in October 2005, welcoming more than 240,000 visitors in its first year.
Alun Pugh, the Welsh Assembly Government minister for culture, calls the museum, which was one of the first large-scale partnerships between NMW and a local authority, 'one of the highlights of [his] ministerial career'. The opening of the waterfront museum marked the end of NMW's £35m strategy to develop its industrial museums.
'An important focus of the past year or so has been internal capacity building, to upgrade storage and other elements,' says Wiliam. 'Now we are implementing our big strategic plans for the rest of the decade.' These will focus on two of the seven NMW sites: the National Museum Cardiff and St Fagans: National History Museum.
The National Museum Cardiff is a two-storey building dating mainly from the 1920s, and currently housing art and scientific collections. It will be upgraded and re-roofed with a £3m grant from the Welsh Assembly contributing to a total of £4.5m that NMW will spend on the development of its art collections over the next two years.
The collections at the National Museum Cardiff will be separated out and some moved to St Fagans, which is five miles from the city centre. The national art collection, which boasts the finest impressionist collection outside France, will be housed on the second floor of the National Museum Cardiff, while natural history and geology will be displayed on the first floor.
The Origins archaeology exhibition opens at the end of this year at the National Museum Cardiff, and will form an important part of the centenary celebrations. But this is an interim measure as archaeology will eventually be transferred to St Fagans along with human history.
'The open-air museum at St Fagans is already the most-visited museum site in Wales and bringing these collections here makes sense,' says Wiliam.
St Fagans will benefit from £12m-£15m being spent on it as part of the redevelopment of the whole site. This includes the recently opened Oriel 1 gallery, where the first exhibition is called Belonging and looks at the theme of Welsh identity.
For the national museums, the Welsh Assembly Government's free-entry policy appears to have been a remarkable success story. The rise in visitor numbers since free admission started on 1 April 2001 has been maintained.
In the first year, visitor figures shot up by 87 per cent. In the past two years, they have been 77 per cent and 80 per cent respectively above the level for 2000-01, the last year of charging.
John Marjoram, the development officer for the Federation of Museums and Galleries of Wales and the Museums Association, says there are several factors that set museums in Wales apart: 'It is important to remember that Wales has a distinct culture and, as a bilingual country, interpretation has to be in both Welsh and English.'
Although independent museums account for much of the sector, they are often small and isolated, Marjoram says. He adds that NMW's high concentration of collections and professionals has meant that the majority of the sector is based in south Wales. 'The north was something of a museum desert until 25 years ago,' he says.
Despite the lack of resources, some local and independent museums have development plans. The independent Abertillery and District Museum opens a lottery-funded refurbishment next month and Caerphilly Borough Council is developing the Elliot Colliery Winding House at New Tredegar as a £2.5m county museum.
The national museums and Pembrokeshire Coast National Park have joined forces to develop a Graham Sutherland Gallery in St Davids, which will be a dedicated year-round attraction for the area, which the 20th-century painter visited frequently.
Cardiff has not had a local history museum since it gave up its collections to attract a national museum in 1907. Plans to re-create it have been ongoing for 20 years, says Anna Smith, Cardiff Council's museum project officer.
The council, which has allocated £1.5m towards Cardiff Museum, is aiming for a spring 2010 opening, subject to a successful Heritage Lottery Fund bid towards the £4m capital cost.
'We have come full circle because the new museum will be housed in the Old Library building, which is where the original 19th-century museum was based, on the top floor,' she says. 'Cardiff was the greatest coal-exporting port a century ago, and the main focus of the new museum will be to tell the story of this rapid industrial rise, and of the people of Cardiff and their stories.'
An exhibition programme, which has been running for three years, has generated a profile and material for the new museum. The building has had a chequered history, as it was also the home of the failed Centre for Visual Arts, but Smith emphasises that the new museum will be free and with more local relevance.
The bridge between local and national museums has been provided by the Sharing Treasures scheme, which helps local museums to establish partnerships with NMW to facilitate the loan of items from the national collections.
It also enables exhibitions and other services from NMW to be delivered at a local level. The initiative makes £55,000 available each year, with museums accepted into the scheme for two years.
Sharing Treasures ensures local mu-seums have the appropriate security and environment to take national loans, but just as important is the skill-sharing aspect of the scheme, says Lesley-Anne Kerr, the head of access, learning and information and communications technologies at CyMAL, a policy division of the Welsh Assembly Government, which administers the scheme.
'It has given staff at smaller, local and independent museums the opportunity to work with the curators, designers and educational staff from NMW,' she says. 'One scheme at Carmarthen Museum was Dinosaurs in your Garden, where staff worked with NMW geologists, who also arranged a full assessment of their collection.'
'The assembly has been great for us,' says Deborah Wildgust, the curator at Pontypool Museum, which is run by Torfaen Museum Trust and was the only independent museum in the Sharing Treasures pilot scheme. 'We have had access to funds, advice and expertise
that we would never be able to afford otherwise.'
Pontypool has benefited from two projects. A suite of dining chairs from a house in the town was loaned from the National Museum Cardiff, and Wildgust and her staff worked with NMW designers and conservators.
'A school for the blind moved into the building next door and we were able to create a Braille interpretation and touchy-feely pictures, and to get the equipment to project the original wallpaper on to the walls,' she says.
The second project involved the NMW Japanware collection that is now on display in a specially designed showcase in Pontypool. 'It is fantastic to have the physical objects, but the background of professional advice and skills has been wonderful, too,' adds Wildgust.
The other issue that has dogged the cultural sector for years has been the idea for a national gallery for art. A steering group is commissioning a feasibility study of the available options.
Alun Gruffydd, the director of Anglesey County Council's Museums and Culture Service, says there is room for a national gallery, but there should be two-way traffic. 'Schemes such as Sharing Treasures has shown how successful that can be,' he says.
The museum service in Anglesey has expanded significantly over the past decade and has further ambitions. It now runs four museums and three heritage sites, including the only working windmill in Wales and a restored bakery and mill complex.
The main site is Oriel Ynys Môn, in Llangefni, which is dedicated to the work of Sir Kyffin Williams, considered Wales's greatest artist and someone with an international profile. Williams died in 2006 and plans to extend the gallery to show more of his vast collection are now advanced.
The £1.6m capital cost will be met by Anglesey County Council, the Arts Council of Wales and the Welsh Assembly, with sales of prints of Williams's work also contributing money.
Gruffydd says a previous emphasis on beach holidays meant there wasn't enough dialogue between tourism and the museum and heritage sector. 'Councils now realise the importance of culture to tourism, and that museums are not just somewhere for holidaymakers to go when it is raining.'
Deborah Mulhearn is freelance journalist
Structure of museums and galleries in Wales
There are 89 accredited museums across the country. Devolved government means that the Welsh Assembly Government has different policies and programmes relating to culture, and those in England do not apply. Amgueddfa Cymru (National Museum Wales) is directly funded by the Welsh Assembly Government.
Museums Archives and Libraries Wales, or CyMAL as it is known, is a policy division of the Welsh Assembly Government based in Aberystwyth. It was set up in 2004 to replace the Council of Museums in Wales (CMW) and provides policy advice to the minister for culture. It also has a developmental role, providing advice and support to the sector.