I think the place might be Buddhist structure. But Info are obscure and more researches need to be done.
The following are some excerpts from wikipedia: " Kurumbera Fort is situated in a village named Gaganeshwar, not serviced by any buses. To reach Gaganeshwar, take the State Highway to Keshiari, at about 27 km from Kharagpur, turn left towards Belda and reach a village junction called Kukai, at about 2 km from Keshiari. Turn to the right into a "Kutcha" (Mud) road, Gaganeshwar village lies at about 2km from Kukai....Built in the year 1438-1469 (written in Oriya inscription) during Kapileswar Deb's period, it also has structures built during the Aurangazeb's period by Mohammed Tahir(stone inscription). Despite being a protected monument, under the ASI, there is no data available about this fort. Folk legends believe that the fort was built in a single night, when Ram, Sita visited the place, during their Vanvas....The fort contains a three domed structure over a platform , along with a sacrificial altar. Though the most parts of this fort and its structures are in ruins, the ASI, has taken considerable effort to protect the structures from collapsing by using cement and lime mortar for holding the external pillars. The pillars hold a roofing which is shaped as a flower. The usage of circular pillar to the rear of the left-dome seems interesting. The presence of an inscription stating about its usage is present right behind of the domed structure. Though the script resembles Oriya, locals state that it is not decipherable." from Wikipedia (http://en.wikipedia.org/wiki/Kurumbera_Fort)
Tarun Tapas Mukherjee
Assistance Professor in English
P.O. Dantan, Dist. Paschim Medinipur, India, PIN 721426
Rupkatha Journal on Interdisciplinary Studies in Humanities