It is Iran's most notorious jail, renowned for housing political activists, but if Tehran's mayor has his way Evin Prison will close and be transformed into a public park.
A concrete monstrosity, guarded by razor wire atop high walls on the edge of a highway in the north of the capital, Evin has been a target of reports by rights monitors such as Amnesty International, alleging maltreatment of inmates by authorities there.
But Mayor Mohammad Bagher Ghalibaf, a former Revolutionary Guards Air Force commander, has plans to demolish the complex and turn its sprawling 43-hectares (106 acres) into a green space.
It would be a radical change for the prison site. A special wing houses academics, intellectuals and journalists, while other sections hold thousands of other offenders.
Jason Rezaian, The Washington Post's correspondent in Tehran, is currently detained at Evin as he awaits trial for espionage and three other charges.
Many political activists arrested after demonstrations that followed the disputed re-election in 2009 of former president Mahmoud Ahmadinejad were also held there.
But Ghalibaf believes that after 44 years Evin's days of locking people up are now numbered, after plans were presented to the judiciary two months ago seeking to change its purpose.
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"We can reach an agreement whereby the Tehran municipality assumes part of the cost and we turn the Evin complex into a park," he was quoted as saying on the local government's website and by news agencies.
Officials have previously announced moves to move prisons and military bases outside the capital.
Evin has been a detention centre since before the 1979 Islamic revolution, having been built by the Shah who was toppled from power that year.
Ghalibaf cited the example of Ghasr prison, a much older facility that was closed in 2008 and turned into a museum as a precedent.
He said negotiations were continuing on the future of Evin, but the aim is to increase the capital's leisure areas for families.
Last week Ghalibaf, who unsuccessfully ran for president in 2005 and 2013, won praise for a scheme that saw billboards carrying famous works of art spring up overnight in Tehran.
That project -- A Gallery As Big As A Town -- showcased reproductions of works by hundreds of famous western, Asian and Iranian artists lining the capital's streets and motorways.
Vincent Van Gogh's Sunflowers, Edvard Munch's The Scream and The Blue Window by Henry Matisse are among the works featured, aiming to get more citizens interested in art and encourage gallery visits.