The Pothgul Viharaya is exactly as its name suggests, a library and monastery complex. It is the oldest one in the whole of Sri Lanka. The term “Pothgul” literally translating as a place to store books. It was constructed under the sponsorship of Parakramabahu of Polonnaruwa (1153-1185 AD ruling period). Thereafter, it was renovated under the patronage of his consort Queen Chandrawathie.The plan of the complex is set in a square set of foundations. Then a number of them within the others with a circular structure in the center of the smallest and innermost square. This may have been the main area for storing books. It may have been completely composed of bricks, covering a rather large area within its confines. The roof of Pothgul Viharaya has been made from either the same material, or from tiles. But much of the building has fallen apart, destroyed over the centuries. In the four corners around the circular building are four little stupas. Also brick structures while there is also a chamber for the monks who resided here. This, the awasa hall is only preserved as a small building with a few stone columns and a rather high stone foundation. The columns must have supported a roof, or else might have had a few more stories to it in real life.
King Parakamabahu built Pothgul Viharaya in the twelfth century and was renovated by Queen Chandrawathi, a consort of King Parakarmabahu. The King used to listen to the Jataka stories of the Lord Buddha told by his teacher while sitting in the circular room.
Pothgul Viharaya is a Gedige type structure, built in the middle of the square shape stage. The main library and the roof, all are made of brick, there are four small stupas at the corners of the floor, and it consists of four terraces. The first terrace is the one that covers a larger area. The upper two patios are the ones that hold the buildings and the third level terrace has nine regions which were considered to be for the 'kutis' for the monks. There are three entrances to the monastery, and the main entrance is the one in the Eastern direction. The uppermost terrace has the circular building which earlier had a circular roof which is also thought to be the 'Mandala Mandira' or the Circular House, built by King Parakramabahu the Great.