The Archeological Sites of the Deltaic Landscape are a series of old mosques and burial sites in Western Bangladesh.  Most are well off the beaten path, and even the sites I visited in Barbobaza where not known by my guide or driver.   

There are 48 listed sites, and about 6 of them are located around the town of Barobaza, which was located along the road to Khulna from Rajshahi (where we were heading to go to the Sunarbans.  Of the sites in the area a few are just old burial mounds that are not in very good shape.  There are two old mosques in the town that are also listed: Gorar and Golkata Mosque.   Gorar is in the attached picture and was quite beautiful, especially the interior.  It's estimated to be from the 15th century.  There is an information sign, but it doesn't say much.   The place gets almost no tourists, especially foreigners.   About 800 meters up the road is the Golakata mosque. This mosque sees probably even less people and it was adjacent to a family farm.  The family who lived there were definitely surprised to see a visitor but didn't mind my sister and I walking around.   

We also tried to find the burial places in town, but the villagers told our guides they were nothing to see or had been destroyed.  Not sure if this was accurate or they were located on someone's land.  

I didn't see enough of this tentative site to know if it should qualify as a WHS.  But if you are going between Bangladesh's WHS and pass them Barobazar the mosques are definitely worth a visit and you will most likely be a curiosity for the local residents.