Ratu Boko is located about 3 km south of Prambanan. Ratu Boko is situated atop of a hill ± 195.97 m above sea level. Ratu Boko is not a temple, but a remains of a palace. Ratu Baka is often called Kraton Ratu Boko. Legend said that Ratu Boko once a palace for Ratu Boko, the father of Lara Jonggrang. Ratu Boko is built during the 8th century AD by the Buddhist Syailendra Dynasty, but then the Hindu Mataram kings took over the place. This take over makes Kraton Ratu Boko is full of Hindu and Buddhist references.
A stele was found in Ratu Boko dated 792 AD named Prasasti Abhayagiriwihara. This stele signs that the Ratu Boko was built by Rakai Panangkaran. Prasasti Abhayagiriwihara is written with Pranagari font, a font used by many Buddhist Steles. In the stele was mentioned Raja Tejapurnama Panangkarana, which is another name for Rakai Panangkaran. Tejapurnama Panagkarana ordered the construction of Abhayagiriwihara. The same name also mentioned in Kalasan Stele (779AD), Mantyasih Stele (907AD), and Wanua Tengah III Stele (908AD). Abhaya means peaceful, giri means hill or mountain. Abhayagiriwihara means a monastery built on a hill of peace. During the reign of Rakai Walaing Pu Kombayoni (898-908AD), Abhayagiriwihara changed its name to Kraton Walaing.
There are some parts of Ratu Boko, the Gate, Batukapur Temple, Pembakaran Temple, Paseban, Pendapa, Keputren and Caves.