User blog comment:Dolten/Call of Duty: Black Ops Achievements/Trophies (SPOILER ALERT)/@comment-1660127-20101001225733/@comment-789991-20101001232125

Rebirth Island is a real location in Russia. it was a research lab for open air testing for things like weaponized Anthrax. It's been shut down for a number of years, but it was active during the time period the game was set it.

http://en.wikipedia.org/wiki/Vozrozhdeniya