Ока
The Shukhov Tower on the Oka River (also Dzerzhinsk High-Voltage Mast, Shukhov Oka Tower) is the world’s only diagrid hyperboloid transmission tower. It is located in Russia, in the western suburbs of Nizhny Novgorod, on the left bank of the Oka River near Dzerzhinsk (about 12 km away from the city center, near Dachny village). The tower is one of several structures designed by Russian engineer and scientist Vladimir Shukhov; its power lines, however, were decommissioned in 1989.