The two major theories for the arrival of Hinduism in Indonesia include that South Indian sea traders brought Hinduism with them, and second being that Indonesian royalty welcomed Indian religions and culture, and it is they who first adopted these spiritual ideas followed by the masses. Indonesian islands adopted both Hindu and Buddhist ideas, fusing them with pre-existing native folk religion and Animist beliefs. In the 4th century, the kingdom of Kutai in East Kalimantan, Tarumanagara in West Java, and Holing (Kalingga) in Central Java, were among the early Hindu states established in the region. Excavations between 1950 and 2005, particularly at the Cibuaya and Batujaya sites, suggests that Tarumanagara revered deity Wisnu (Vishnu) of Hinduism. Ancient Hindu kingdoms of Java built many square temples, named rivers on the island as Gomati and Ganges, and completed major irrigation and infrastructure projects.