The pulp-and-paper, timber and woodworking industries ("JSC Svetogorsk", pulp and paper mill in Svetogorsk, "Vyborgsky Pulp and Paper Mill" in Vyborg, "Priozersky Furniture and Woodworking Industrial Complex" and "Priozersky Woodworking Factory" in Priozersk, as well as other smaller enterprises all over the isthmus) are well developed in Vyborgsky and Priozersky Districts. The pulp and paper industry, however, affects the environment adversely. The predecessor of the Priozersk facilities, "Priozersky Pulp and Paper Mill", a major polluter of Lake Ladoga constructed in 1931, was closed down in 1986. Northern and western parts of the isthmus are also an important reserve of granite (quarries in Kuznechnoye, as well as a number of others along the Vyborg-Hiitola railroad).