Three temples in Thanjavur and Ariyalur districts, namely the Brihadisvara temple, Iravateswarawamy temple and the Big temple at Gangaikondacholapuram built by the great Chola kings have been declared as world heritage monuments by the United Nations Educational Scientific and Cultural Organisation (UNESCO).

The Brihadisvara temple at Thanjavur built by Raja Raja Cholan is celebrating its millenium this year; the Iravateswarawamy temple at Darasuram near Kumbkonam was built by Raja Raja II and the Big temple at Gangaikondacholapuram was built by Rajendran Cholan, son of Raja Raja Cholan in Ariyalur district.

The three temples are in stone and have almost same architecture and design except for the size. While the Big Temple at Thanjavur remains colossal in all its aspects — a towering Vimana with a height of 212 ft, a big Linga in the sanctum sanctorum, a huge Nandi in the front and Goddess Periyanayaki also standing tall, Darasuram and Gangaikondacholapuram account for smaller forms of the Big temple. Despite the general concept of a chariot being pulled, the sculptures differ in the three temples.

The Archaeological Survey of India (ASI) maintains the three temples well and has almost reconstructed the whole temple at Darasuram.

The construction of the Big Temple — also known as Rajarajeswaran Udaiyar after the great king — began in 1003A.D. and was consecrated for worship on 275th day of the 25th year of the King’s reign (1010 A.D.). The temple is 1000 years old this year (2010). This edifice is one of the finest and most exquisite specimens of the Chola architecture. Dedicated to Lord Siva, it is located within a spacious inner courtyard measuring 240 X120 m. The temple is replete with inscriptions relating to its origin and endowments and also sports a profusion of friezes from the epics.