Poddar bari, or according to the local people, the "panam raj bari". This is a bit eastern side to the panam city. If you want to visit the place, you have to pass through the panam city.
If you are visiting the panam city by feet, then you have to walk until you are reached to a T shaped road, and you have to take the left side of the T. Few steps from the T, its the poddar bari. Or you can take a rickshaw from panam city, and it will cost you 8-10 taka for the lift.
This is currently a private property, and there is a picnic spot inside the boundary of the place. Also the owner of the place used to live at the newly built building beside the old one. But the old one is still empty. After taking permission you can easily enter the area.
Its not known when the building was actually built. But from the structure, and the design, it appears that it was built by some rich merchant during the 1900 AD. The structure and the design is almost identical the Sonargaon Museum.
Inside the building, the yard is identical to the museum building of sonargaon. I've found only the yard of the building has some light, and other rooms are almost dark. Its hard to move inside the building without a light. So you need to be careful for that.
The building comprises of numerous number of rooms. And interestingly you can move from one room to another one easily. There is no window at the rooms, and also no doors, most of those are taken down, or stolen, or something else.
Since its a bit darker inside the building, its a hideout for the bats. When i have first flashed my camera, I have seen several bats were flying and making noisy sound. Also there nest of other birds which are making continuum sound, but believe me you won't feel bored by those. Those are really nice to hear.
So if you are at sonargaon, please don't leave the place by only visiting the panam city. It will worth if you visit the place. I have enjoyed the place.