[1] The Metris prison is situated in the Havaalanı neighborhood on the Eskiedirne Asfaltı (literally: Old Edirne Road).

[2] The facility was established by the Ministry of National Defence and opened on April 17, 1981, for use as the Metris Military Prison during the martial law era following the 1980 coup d'état.

[2] Twenty-nine inmates escaped from the prison in the early hours of March 25, 1988, as it was still being administered by the military.

[3] The mass prison break took place through a 60 m (200 ft)-long secret tunnel, which was built in six months.

[3] The tunnel was dug up manually with spoons, and the extracted soil was dumped into the sewage system.