The island is 52 square kilometres in area and is uninhabited apart from a rich variety of wildlife including rare birds, wild horses, mouflon and a unique herd of wild, albino donkeys from which it is thought that the island takes its name.
Prehistoric houses were found on the island near Campu Perdu. These houses, carved into the limestone, are known as 'Domus de Janas' which translates as 'Sprites' houses', and are unique to Asinara. The island shares the common Mediterranean history of colonisation by the Phoenicians, Greeks and Romans. It was attacked by pirates and fought over by the Aragons and the city states of Pisa and Genoa before eventually becoming part of the kingdom of Italy.
In 1885 a quarantine hospital and a prison were set up and the 500 or so inhabitants were made to leave the island. They established the nearby town of Stintino on the main island of Sardinia.
During the 1st world war, 24,000 prisoners were incarcerated on the island and later, in the 70s, the prison was used to house Italy's most dangerous terrorists and Mafia members, including the infamous Toto Rina. Over the 112 years that the island operated as a prison, only two people escaped, the lowest number of escapees from any prison in the world.
The prison was closed in 1997 and Asinara became a national park. Although it is forbidden for private boats to stop at the island, it is possible for tourists to visit the island on guided tours. Fishing trips and diving excursions are also permitted on a limited and strictly supervised basis.