Taman sari water castle is a very beautiful historical place in Yogyakarta, Indonesia.

During the mid-18th century, the Sultanate of Yogyakarta began work on Taman Sari Water Castle. Comprised of lavish gardens and pools, Taman Sari also featured a bizarre man-made sea, connected beneath the ground with underwater tunnels and small island buildings. One of these island structures was used as a mosque, and was only accessible by underwater passage.