Bolshoye Svyatoye Lake, Protected lake in Navashinsky District, Russia

Bolshoye Svyatoye is a freshwater lake located in the Navashinsky District with natural shorelines and diverse aquatic vegetation throughout its waters. The lake forms the centerpiece of a protected area that supports various water-dependent wildlife.

Bolshoye Svyatoye formed in a karst sinkhole, a depression left when underground rock dissolved. It has been protected as a regional natural monument since 1976. A local legend tells that the trading village of Rusaki with its monastery once stood on the site and that icons floated up after the collapse.

The lake is also called Dedovskoye after the village of Dedovo nearby. A local legend tells that a wealthy trading village, Rusaki, with a monastery once stood on the site; after the karst collapse, icons floated up from the monastery, and the water is considered holy. In summer the lake draws many holidaymakers, mainly from Murom and Navashin.

The lake lies in the north-western part of the Navashinsky urban district, in the Tyosha river basin, near the village of Dedovo. In summer it draws many holidaymakers, mainly from Murom and Navashin, so the shores are busiest in the warm season. The site has been a regional nature monument under state protection since 1976.

The lake's name, Bolshoye Svyatoye, means "Great Holy," and locals also call it Dedovskoye after the nearby village of Dedovo. A legend says a rich trading village called Rusaki with a monastery once stood on the site; after the karst collapse, icons floated up from the monastery, and the water is still considered holy.