I highly recommend you to visit this place, and ready to guide you, because this place is my Doctorate Final Project from University of Canberra  (2000-2005)

Taman Sari also known as Taman Sari Water Castle is a site of a former royal garden of the Sultanate of Yogyakarta. It is located about 2 km south within the grounds of the Kraton, Yogyakarta, Indonesia. Built in mid 18th century, the Taman Sari had multiple functions, such as a resting area, a workshop, a meditation area, a defense area, and a hiding place.

http://en.wikipedia.org/wiki/Taman_Sari_(Yogyakarta)

Gapuro Agung – West Gate

Gedong Kenongo which surrounded by Segaran Lake (long long time ago)

Gapuro Panggung – East Gate

more information, you may buy my book :

http://www.amazon.com/Taman-Sari-Yogyakarta-Defense-Systems/dp/3838327047

Here the air-photograph, maybe can give more information :