Troki uezd
The Troki uezd was a county of the Vilna Governorate of the Russian Empire. The uezd was bordered by the Mariampol, Kalvariya, and the Seyny uezds of the Suwałki Governorate to the west, the Lida uezd to the south, the Vilna uezd to the east, and the Kovno uezd of the Kovno Governorate to the north. The administrative centre of the county was the city of Troki. The area included most of the modern Trakai, Elektrėnai districts of Vilnius County, and Varėna, Šalčininkai districts of Alytus County, as well as part of Kaišiadorys, Alytus, and Prienai districts.