Protva River, a river in Moscow and Kaluga Oblasts of Russia; left tributary of the Oka
In Russian stratigraphy, the Serpukhovian is subdivided into three substages, from bottom to top: Tarusian, Steshevian, and Protvian, named after places near Serpukhov (see Tarusa, Protva).
Protva River | Protva |