An integral part of a Buddhist monastery is the Sannipata Salawa or the Assembly Hall where the Bhikkhus of the monastery met to discuss matters of common interest pertaining to the rules of discipline administration.
The most senior Bhikkhu of the Vihara and took the chair at such meetings. In the case of Mihintale we see from the inscription in the neighbourhood that the senior Bhikkhu of the Vihara was called the Naka balana himi meaning the chief Bhikkhu of the fraternity.
The elevated stone seat that you see in the middle of the hall was meant for him. From the building it is quite clear that the Assembly Hall is situated in a central place in the huge monastic complex where monks could meet at a short notice.
This building which was used for common purposes included the preaching of Dhamma. It is also interesting from an architectural point of view.
The Hall is square in plan with a side about 62 feet in length. It had no enclosing walls or rooms attached to it. The roof was carried by symmetrically arranged stone pillars that still survive though now without the roof.
There would have been about 64 (8×8) such pillars. The Hall had access from all four directions with flight of steps. The open nature of the building would have been environmentally suitable for a place of congregation in a dry climate.