The bunker, which was designed to withstand a nuclear attack, will close next Monday and the jewels will be polished before being transferred, amid high security, to the new pounds 10m Jewel House, which will open to the public on 24 March. It is above ground level in the Waterloo Barracks, just above their old home.
The present bunker was designed to accommodate 5,000 visitors a day but at the height of the tourist season up to 15,000 people queue to see the jewels. People in wheelchairs have been unable to negotiate the 49 steps below ground.
The project, paid for by Historic Royal Palaces, the government agency that now makes pounds 4m a year, will enable visitors to see the most important jewels from a moving walkway designed to prevent a crush.
Those who wish to take a longer look can linger on a viewing platform behind the walkway. Critics say that people will not have time to see the jewels properly.
The crowns, sceptres and orbs will be in glass cases within touching distance of visitors. But Colonel Hamish Mackinlay, deputy governor of the Tower of London, said: 'The glass is made to standards required to maintain the security that we have now.'
The jewels, displayed on silk cushions in dimly-lit rooms and illuminated by fibre optics, will be guarded by wardens, backed up by 'state-of-the-art security technology'.