Kalyazinsky District is an administrative and municipal district (raion), one of the thirty-six in Tver Oblast, Russia. It is located in the southeast of the oblast and borders with Uglichsky District of Yaroslavl Oblast in the northeast, Pereslavsky District of Yaroslavl Oblast in the southeast, Sergiyevo-Posadsky District of Moscow Oblast in the south, Taldomsky District, also of Moscow Oblast, in the southwest, Kimrsky District in the west, and with Kashinsky District in the northwest. The area of the district is 1,671 square kilometers (645 sq mi). Its administrative center is the town of Kalyazin. Population: 21,688 ; 24,460 (2002 Census); 27,341 (1989 Soviet census). The population of Kalyazin accounts for 63.9% of the district's total population.

Kimrsky District is an administrative and municipal district (raion), one of the thirty-six in Tver Oblast, Russia. It is located in the southeast of the oblast and borders with Kalyazinsky District in the northeast, Taldomsky District of Moscow Oblast and the town of Dubna, also of Moscow Oblast, in the south, Konakovsky District in the southwest, Kalininsky District in the west, and with Rameshkovsky District in the northwest. The area of the district is 2,514 square kilometers (971 sq mi). Its administrative center is the town of Kimry. Population: 13,190 ; 15,604 (2002 Census); 18,439 (1989 Soviet census).