Centuries ago it was fit for a queen.

And when the garden is completed in 2009 it is hoped that it will meet with royal approval for a second time as English Heritage has asked Queen Elizabeth II to officially open the attraction.

Whilst a reply is still awaited from Buckingham Palace, the work continues using Robert Langham's detailed description of the gardens in his letter from 1575.

Every detail, from the jewels in the aviary to the 'fake' stone obelisks are being reproduced so that visitors will eventually be able to enjoy walking along the same paths as Queen Elizabeth I herself.

Visitors to the garden taking advantage of the Friday tours, will already have seen the garden begin to take shape.

The base for the aviary has been laid and research into what birds will thrive the best has already been undertaken.

Selina Fox of English Heritage said: "The letter described the most beautiful and exotic birds, but in those days the aviary would not have been suitable for those sorts of birds to survive, but then they perhaps wouldn't have cared so much about that sort of thing. These days we obviously do so have been researching what birds are best to house there."

Steve Bax at the castle, added: "We have been learning so much about birds and we think there will mainly be canaries in the aviary, which will be fitted with special lighting to mimic the sun so the birds will feel comfortable.

"We also hope to have some peacocks roaming around to add to the authenticity."

Plants and fruit trees will form a large part of the garden.

Tamsin Rosewell who gives tours of the garden said: "In Elizabethan times gardens told stories.

"Certain smells would provoke memories and thoughts. When we walk through a lovely garden we appreciate it but we view it very differently to how an Elizabethan would have."

As well as the aviary, bases have been created for the 18ft marble fountain, which had been the centrepiece of the Elizabethan garden.