There are tens of thousands of Hindu temples where Shiva is either the primary deity or reverentially included in anthropomorphic or aniconic form (lingam, or svayambhu). Numerous historic Shaiva temples have survived in Tamil Nadu, Kerala, parts of Andhra Pradesh and Karnataka. Certain regions have a greater density of Shiva temples, such as in the Thanjavur region of Tamil Nadu, where numerous Shaiva temples were built during the Chola empire era, between 800 and 1200 CE. Gudimallam is the oldest known lingam and has been dated to between 3rd to 1st-century BCE. It is a carved five feet high stone lingam with an anthropomorphic image of Shiva on one side. This ancient lingam is in Chittoor district of Andhra Pradesh.