Belle Reve Correctional was an American prison.
In the comics, Belle Reve is a metahuman prison in Terrebonne Parish, Louisiana. Waller recruits her Suicide Squad members there. The name is derived from a Mississippi plantation of the same name in Tennessee Williams' A Streetcar Named Desire.
In the DCAU, the location of Belle Reve is never revealed. Louisiana does not use the gas chamber as a means of execution, though this discrepancy can be ascribed to a Californian writer (similar to Superman: The Animated Series, "The Late Mr. Kent").