Ambitious plans to plough millions of pounds into a major reamp of Norwich Castle Museum have been revealed.

Smart phone technology, wall projections and giant display cases to showcase treasures from Norfolk and British Museum are among the latest ideas being explored for the iconic building's keep.

Staff from the Norfolk Museums and Archaeology Service say they are planning to submit 'big funding bids' in the next 18 months, which if successful will change the keep's appearance to visitors.

The Evening News understands the funding bids will aim to attract a cash sum in the millions. Potential sources include lottery cash.

Project officials say there is no target figure, although a total will become clearer in time.

They hope to complete a project by 2014/15 that creates a wow factor, makes the castle an attraction the region can be proud of and encourages people to revisit.

But first they will speak to the public to find out what they want. Focus groups are planned to start in March.

Dr John Davies, chief curator and keeper of archaeology, from the county's museum service, said: 'Norwich was one of the richest provincial cities in Britain during the medieval period.

'It was a regional capital of national and international significance. Our ambition is to make Norwich's wonderful Norman Castle keep the display venue for a new interpretation of the history of Norman and medieval Norwich.'

A first look at how Norwich Castle's keep could be designed in the future has been revealed.

The 11th century structure has previously been designed to perform the roles of royal palace, gaol and prison.

And now the keep is in line to be refreshed for the first time in more than a decade.

The artist's impressions show initial ideas of how exhibits from Norfolk and the British Museum could be displayed.

Sketches of how the colours and decor of the medieval-era might be recreated are also unveiled.

Staff have spent almost 12 months working on the Gateway to Medieval England project and trying to establish how to make the attraction stand out. This includes working with the British Museum to allow objects from London to be brought to Norwich. Ideas for how to develop the city museum have been already tested.

It is expected feedback from visitors will help influence how the castle is displayed in the future.

Emma Taylor, Norwich museums development officer, said there were a number of new technological toys available to bring history to life.

She said: 'It's 10 years further down the line and more than a million visitors have gone through the museum in that time and we wanted to revisit it and be really ambitious.

'There are so many opportunities with technology, such as virtual reconstructions of how the castle could have looked in the Norman period and bringing in to use people's smart phones.'

Ms Taylor said it was important to listen to what the public wanted to get the most out of the project.

She said: 'We are doing a lot of talking to people about what they would like. There will be some really big funding bids next year or the end of this year. We will really go for it and get some big money to get a wonderful project.

'It's not going to be easy to get it right but I am sure we can.'

Castle Museum staff have also been working with their counterparts at French medieval castles. The project is known as Norman Connections and is being made possible by �160,000 of European Union cash. It hopes to bring together ideas and knowledge of how to display history from tourism services and Norman heritage sites in the south of England and Normandy, in France.

Dr Davies said: 'Norwich Castle is also in close collaboration with European partners in Caen, Bayeux, Falaise and Calvados in Normandy, Rochester, Hastings and Colchester in England. Working with these partners, we are jointly exploring ways of interpreting our Norman Castle sites in their international context.'

George Nobbs, a county councillor and member of the Norwich area museums committee, said: 'We must always be very careful when we make changes to the castle that we take along the people of Norwich with us as they have demonstrated recently that they are very fond of their museums.

'Before anything is done there should be a meaningful consultation, not just a paper one or paying lip service but the fullest possible one.

'No change should be made unless it's an improvement.'