The Agastisvara temple is the larger of the two twin shrines of the Avani-Kandrapa-Isvaram temple at Kilaiyur belonging to the reign of Aditya I (871-907 CE). The other one is called the Colisvara temple. The earliest incontrovertible inscriptions on this temple are dated in Parantaka I's years (907 - 954 CE) though it has also been suggested that there are at least three inscriptions that belong to Aditya I's time. The stone of the main building is granite and that of the hall is a corrosive yellow stone. The names of the donors are inscribed on the pillars. The shrine is a prototype of early Chola art. The scrollwork over the jambs and lintels of the doorway is most ornamental. Another interesting feature is that the superstructure (vimana) is square and with a square finial (stupi) unlike its twin shrine that has a circular vimana and stupi. References: S.R. Balasubrahmanyam, 1963, pp.13-20; M.W. Meister and M.A. Dhaky, EITA, Lower Dravidadesa, Text, 1983, 215-18.