'''Optina Pustyn''' , officially '''Svyato-Vvedenskaya Optinakaya Pustyn'''<ref>A. Osipova, "Optina Pustyn", ''Russian Life'', Vol. 51, No. 2, ISSN 1066-999X #523</ref>, is a male [[monastery]] near Kozelsk which was the most important spiritual center of the [[Church of Russia]] in the nineteenth century. The monastery was famous for the [[monasticism|monastic]] renewal movement in Russia based on the [[hesychasm|hesychastic]] tradition that had been largely lost in the Russian monastic experience in the eighteenth century.