This is one of the oldest prisons in Russia and one of the first prison for life in the Orenburg region. Originally it was a jail (Ostrog) for a lifetime of hard labor. The first mention of this relates to 1745. After the suppression of the Pugachev's Rebellion in 1773, the prison was built for the deportation of robbers. The prison got its unofficial name from a fountain with a sculpture depicting a black dolphin, which is set before the main entrance. The sculpture was made by the prisoners themselves.