Although there is a strong indication that the Ratu Boko temple is of Buddhist origin, there is interesting and controversial evidence of Hindu remains in the form of lingga, yoni, Ganesha, and Durga Mahissasuramardini. According to the Pereng inscriptions, of 856 A.C., the complex was a palace of local Hindu ruler called Rakai Walaing Pu Kumbhayani. Thus, the function of the complex is so far undiscovered, and a short visit will only give a glance. We recommended sparing time to visit the following sites.
Alun-alun. One of the ruins is a site called alun-alun (town squre). Following the path leading to the site, you will notice foundations of large white stones at its left. The site has a pair of entrance gates (gapura) of andesite. The first has three doors and the second, behind several stone steps, has five. The alun-alun is composed of two squares, measuring 170x20m each and surrounded by a 1,5m-wide pit. On the stone terraces you can see a group of plinths in neat formation, indicating that there was once a pillared building on top, perhaps a pendopo (reception hall). Not far from the plinths there is a brick-and-cement well built by locals, preserved to indicate that the location of the alun-alun was in the recent past inhabited.
Crematory Temple. On the vast ground, you will see a tall platform, bordered by steps, surrounded by parapets and equipped with a basin of white stones. This construction measures 25x10m at the base and 1.5m in height. It functioned as a crematorium for the dead, as practice in the hindu tradition.
Audience Hall. To visit the ruins of the palace, you have to continue to the right (west), through the Dawung village. The site is constructed of two rectangular esplanades of 20x25m, a meter in height, made of andesite rocks. These are thought to once function as a waiting room before an audience with the king. About 10m to the south lies another door in ruin and half destroyed, which is thought to be part of the entourage of the Ratu Boko palace.
Pendopo. To the south of the paseban, through a bit of a teak forest, we will face a pendopo (audience hall) surrounded by a high rock fence of white and andesite rock with three entrance gates. The 40mx30m rectangle of stone blocks retains the plinths of the pillars of a wooden construction it used to support. A part of its floor has larger rocks, which indicates where the wood pillars once stood. The structure has waterspouts, or jaladwaras, outside its fence. Inside the fence there are two separated rooms: Batur Pendopo (10x10m) and Batur Pringgitan (4x10m), connected by a narrow opening with a downward flight of steps.
Miniatur Temple. At the west of the pendopo fence there is an altar of 10x10m with three little gates at one side. The gates, standing side by side, are not higher than 1m and symbolize the three Hindu goods: Brahma, Shiva, Vishnu. The building is often called the miniature temple and is thought to function as a place of worship.
Keputren Pool (Princess' Bath). The most intersting element of the Ratu Boko complex is located at its eastern side, consisting of a group of pool called Keputren (literlly “ladies’ quarters”); some of them still contain water. Some of the pools are cavities dug into the white rocks and lime while others are rectangular pool, sometimes with kala-ornamented gates. You will have a better view stepping onto one of the platforms boerdering them. Fragments of sculputures and bas-reliefs can be found around the pools: elephants, birds, and snakes. Near the bath, stupas are visible; some whole and ithers in ruin. It was here that the Bodhisattva statue, now kept at the Office of Archeologaical Services, was found.
The Lanang and Wadon Caves. To the south of the complex there are two artificial caves called Lanang (male) and Wadon (female). The white-stone Lanang cave, the one situated higher, is larger (about 3m long). The names of these caves come from the discovery of, respectively, a lingga and a yoni inside of them. The caves, until today a place of meditation and contemplation, are eqiupped with a well for washing before prayers. Men will meditate in the Lanang cave and women in the Wadon.
The complex of Ratu (King) Boko site is popularly believed to be royal palace of a king who had the habit of eating human flesh. The habit started in his infancy, when his mother cut herself during cooking. Tasting the blood in the food, he found it so delicious he developed a penchant. As an adult and a king, he sent one soldier every day to find a human prey. If the soldier failed, the king would devour him. The people were terrorized and fled to the neighboring kingdom Pengging, whose king of Pengging tried to find a solution and finally decided to send his son Bandung Bondowoso to fight Boko. After an insight from God and a ferocious battle of ten days, Bandung defeated Ratu Boko.
Source: Situs-Situs Marjinal Jogja (Sanctuaires Retrouvés/ Sites Out of Sight) - M. Rizky Sasono, Jean-Pascal Elbaz, Agung 'Leak' Kurniawan (Enrique indonesia, Yogyakarta: 1997).