in 1996. The Cilacap government then invested some Rp 1.7 billion (around $200,000) in preparations for the opening up of the island, most of which was used on the construction of tourist-related infrastructure. A special agency was also established to manage tourism on the island, with the Nusakambangan Prison warden made head of the agency and Cilacap Tourism Office chief as the deputy. No individual tourists are allowed, all of the tourists within a group of minimum 15 persons which is arranged by tourist agency then will be accompanied by security officers until maximum 6 p.m without overnight stay. Prisons There are nine prisons built in the island, four of which are still used (a fifth super max prison is under construction): Permisan prison, built in 1908, Batu prison, built in 1925, Besi prison, built in 1929, Kembangkuning prison, built in 1950. There are also five inactive prisons: Nirbaya prison, built in 1912, Karanganyar prison, built in 1912, Karangtengah prison, built in 1928, Gliger prison, built in 1929, Limusbuntu prison, built in 1935. All of these were built by the Dutch, except Kembangkuning prison, which was built after independence. Of these, Batu (literally "stone") prison is considered the most famous. It was sensationally called "Alcatraz of Indonesia" in one news article by an American journalist, while another American titled his piece "Execution Island". Notable inmates Famous people imprisoned on the island include: Pramoedya Ananta Toer, poet and novelist, jailed on the island July - August 1969 as political prisoner. Bob Hasan, former Minister of Forestry, convicted of corruption charges, Imam Samudra, Amrozi, and Ali Gufron, three men convicted of organising the 2002 Bali bombing. They were executed there by firing squad on November 9, 2008. Tommy Suharto, son of former president Suharto, convicted of masterminding the murder of the judge who sentenced him for corruption. Fabianus Tibo, Dominggus da Silva and Marianus Riwu, three men convicted as provocateurs and mastermind of a deadly riot in Central Sulawesi; they have been executed there. Australians Andrew Chan and Myuran Sukumaran, the ringleaders of the Bali Nine group were arrested at Denpasar airport in 2005 for drug trafficking and sentenced in 2006 to execution by firing squad. They were executed by firing squad on April 29, 2015. Brazilian Rodrigo Gularte, convicted as drug smuggler. He was executed by firing squad on April 29, 2015. Filipina Mary Jane Veloso, arrested and sentenced to death,