Where is Marvino located in the novel, The First Circle?

Mavrino sits on the outskirts of Moscow. Its prisoners have the occasional chance to visit with family, and they work daily beside free employees. They interact with nearby government agencies overseeing the research. The novel juxtaposes prison society and Soviet society to more closely observe the authoritarian mentality that incarcerates innocent people. It studies the stress of enduring imprisonment, either the comfortable imprisonment of the sharashka's inhabitants or the invisible imprisonment of all Soviet citizens.