Marble Lake

Marble Lake fills a pit left by blasting rock on the Ajodhya plateau, where stone was cut for the Purulia Pumped Storage Project. Steep, banded rock walls drop into deep, still water that turns a strong blue under a clear sky, and it has become one of the most popular stops on the hill circuit. The district administration lists it as Durga Bera.

The lake lies a short way off the road between Ajodhya hill top and Bamni Falls. Blasting opened a deep gash in the rock, springs filled it, and the result is a small lake about 40 feet (12 m) deep, still ringed by the broken stone that was dug out. The district calls it Nil Jal for its colour; local people also know it as Patal Dam and Neel Dam.

It is small, about 2 hectares of water by a 2023 field survey, but the setting is striking: dark water at the bottom of a deep cut, high rock walls above it and the long forested ridge behind. Bengali visitors often compare it to a miniature Grand Canyon, and it draws crowds in the season.

The quarry faces are of real interest to geologists. They expose migmatite banded in light and dark layers, formed when the parent rock partly melted at very high temperatures, cut by younger dolerite dykes and by pegmatite and quartz veins with coarse crystals of quartz, feldspar and mica. Some quartz veins swell and pinch along their length. The 2023 study rated it the only geologically 'unique' lake in the hills.