Pustynsky Reserve is a forest area of 6,200 hectares in the basin of the Seryozha between the settlement of Staraya Pustyn’ and the village of Menshikovo of Arzamas district. Eight karst lakes and two peat bogs, Koz’ye (literally, Goat) and Mostovoe (literally, Bridge), are taken under protection as natural monuments. At the boundary of subzones of mixed forests with oak forests, almost all types of natural landscapes and biocenoses of the midland of European part of the country are gathered in the small territory. The main attraction of Pustynsky natural complex are eight deep water (up to 14 m.) karst lakes: Great, Holy, Deep, Round, Steam, Long, Narbus, and Karasevo, which are connected into a single system with a total area of about 300 hectares. There is something romantic and mysterious in the very names of these lakes and this corner of nature in Nizhny Novgorod oblast. The name of the placec obtained because of the neighboring village of Old Pustyn’ (that is, Russian word for «desert») of Arzamas district was not accidental. Indeed, the places of the densely populated right bank are desert; there are just forests and forests stretching for tens of kilometers along the Serezha. Underground water while dissolving local limestone and gypsum fills potholes emerging on the ground. Half of Pustynsky lakes (Great, Deep, Steam and Long) are running ones; it is them where the river Serezha flows. Gradually turning into bays and lakes from a narrow blue ribbon on its way, it forms a real water maze. Other lakes are very seldom connected with each other by channels so that the water there is like a rock crystal, it is the same clear and clean.