Oka deserves to be defined as remarkable, the same word Mark Twain used in his 1883 memoir «Life on the Mis- sisippi» describing the greatest American river. Oka starches over 1500 kilometers covering 250 000 square kilometers of basin area in the Central Russia. It is listed among the world 100 longest rivers. Its banks are pined by numerous Russian historic towns, churches and monasteries, a vivid reminder of Oka’s role in the historic trade route connecting Scandinavia, Kievan Rus and Byz- antine Empire. The scientist attribute the origins of the name Oka to the ancient Greek word «aqua» as yet another proof of the river’s historic significance to the region. Oka’s importance stretches beyond its physical charac- teristics. For centuries the river had a profound impact on the local communities across Central Russia. Nowadays, it continues to define and shape the environment around it, equally brining joys and challenges to the everyday way of life of the locals.