( CNN ) -- For centuries , it has enchanted visitors with its fortified walls , pointed arches , towers , ornamental flourishes , carvings , and spectacular gardens . The Alhambra , a fortress and palace in the Spanish city of Granada was begun in the mid-13th century by the Nasrid Emirs of Granada , the last Muslim rulers in Spain . Further palaces and Christian chapels were added to the complex in the centuries since , making it a fascinating mix of cultures and histories . Full of mysterious nooks and crannies as well as grand spaces , the Alhambra attracts around two million visitors a year , according to the Patronato de la Alhambra in Spain , the organization that looks after the complex . Now a sustainable tourism effort from the Patronato de la Alhambra , the World Monuments Fund and others is taking the Alhambra into the 21st century , using technology to bring previously hidden areas of the complex to light . Entitled `` The Hidden Alhambra , '' the project aims to expand the site for tourists , with an app . It will allow visitors to virtually explore delicate , closed-off areas on their iPhones , or on specially designed portable electronic tablets , as well as opening up new routes to related areas outside the complex . `` It is a site that gets many visitors , we can say that it 's a major tourist destination , '' said Maria del Mar Villafranca , director of the Patronato de la Alhambra . `` For many years now , we have worked with a model that limits access to a certain number of visitors per day , '' she explained , saying `` Hidden Alhambra , '' is designed to further take the pressure off `` fragile zones . '' Hidden areas that the application will bring to light include an underground space beneath the palace of the Holy Roman Emperor Charles V , as well as storage areas , towers and pavilions , according to Norma Barbacci , Program Director for Latin America , Spain , and Portugal at the World Monuments Fund . `` ( Visitors will ) be able to see images and video ( on their iPhones ) and get all kinds of information about these specific sites that are not open , '' she said . `` They are not able to walk down the stairs into the silos for example , but they can be close to them and get a lot of information , '' she continued . The app is currently being developed and augmented reality features have not been ruled out , said Barbacci . The first phase of information-gathering for the application , namely photographing the various sites , is being undertaken , according to Villafranca . They are aiming to have the app ready for the public by summer 2012 . Virtual visitor experiences are an increasingly popular way of making delicate historic monuments accessible , said Barbacci . `` Once the technology began to improve , then we started looking at this as a way of promoting knowledge and caring for a building without trampling all over it , '' she said . But it 's not all virtual work : The World Monuments Fund is also contributing $ 300,000 to the conservation of the Oratorio del Partal , an elaborate mid-14th century chapel built during the reign of Yusuf I . The conservation effort will include work on the roof , carved wood ceiling and decorative plaster work and will be incorporated into the `` Hidden Alhambra '' application . `` It 's a very important part of the Alhambra , for its symbolic value being a part of the oldest area of the complex , '' explained Villafranca . It is part of a long-term plan of conservation works to other fragile areas of the complex that , she hopes , will make more and more of it accessible to visitors -- and continue to pique their interest in it .
App to make closed - off parts of Moorish palace accessible to tourists . App a ` ` sustainable tourism '' development , says World Wildlife Fund . Around two million people visit it each year , says Patronato de la Ciudad . Area to be broadened for tourists and developed for future .