Is it permissible to build upon a grave, or is it permissible to move it to the town's cemetery or another location?

It is not permissible to desecrate graves by building upon them or by sitting and walking over them, based on the hadith (definition): "For one of you to sit on a burning ember that burns his clothes until it reaches his skin is better for him than to sit on a grave." As for moving the deceased to another place, there is no objection to it if there is a valid reason, but it is preferable that the deceased be moved to Muslim cemeteries for their preservation and protection.