Built in the 2nd-century by King Devanampiya Tissa, this has been the alm hall where Buddhists monks of the Mahaviharaya monastery gathered for their meals. The alms hall is also known as the Mahapali Alms Hall. The hall consists of a massive trough which is built on the model of a canoe and measures up to 45 feet in length and 2 feets in depth. It was identified that in the ancient times this trough must have been surrounded by a series of small rooms or a cloister under an arcade.
Among the few items a Buddhist monk can own is the alms bowl. Monks who are into serious meditations and simplicity goes on alms rounds to find their meals. They consume whatever they receive from whoever they were provided with. It is also believed that the rice canoe in the Mahapali Alms Hall was filled with rice daily for the bhikkhus to consume.
Beside alms halls there is a deep well which must have been used by the Bhikkus. The walls of the square shaped well were made with granite slabs and there are steps to climb down to the bottom of the well.