Enclosed between jungle and inhospitable ocean, French Guiana was for a century an open prison. In this carceral archipelago, 70000 convicts were exposed to deprivation, forced labour, diseases, violence and absolute confinement. 10000 survived. The penal colony had organized a real Darwinian selection. The notion of freedom bore a very particular ambiguity, as the real prison began outside the cells, the absolute confinement of the prison giving way to a more perverse confinement. The newly released person had then the choice between a life exile in an inhospitable land, or escape. The candidates for escape were confronted with the terror of a carceral jungle conducive to epidemics, infections, fever, etc ... or the extreme danger of an ocean infested with sharks, and characterized as well by strong currents, sandbanks and tropical storms announcing death. This study is a reflection on the illusion of freedom, using the historical filter of the Guyanese prison, and the metaphorical image of the window as a border between two antithetic common spaces: the penal colony vestiges, the darkness of its cells, and its leprous walls resonate with the false appearances of a freedom symbolized by the luminous and open spaces of the ocean or of a lush jungle.