Yogyakarta's Water Castle is said to be divided into two complexes, theUmbul Binangun or the swimming pool complex and Pulo Kenongo. Leaving the Umbul Binangun for the Pulo Kenongo was a delightful experience. At one moment, you'd be walking along a walkway which looked perfectly normal and then, suddenly, you would come to an entrance which when you walked in, would transport you into another world. You'd found yourself in an underground tunnel and in olden days, the Sultan himself might as well be walking here as he hid himself from his enemies. There are canals in this area which when flooded with water, hide the tunnels from view. There were supposed to be a few buildings here too, the Kenanga, Cemeti Island and Sumur Gumuling which could still be seen after the canals are flooded and it is said that from a high place, the buildings look like a lotus floating in the middle of a pool...
Tunnels?