in Yogyakarta or Jogja have many culture and language. if you came to joga don't forget visit to "Maliboro". maliboro is central culture in Jogja. jogja is Education city, the Students come from some territory in Indonesian and moreover strange. thanks---
... and try some of the local food "Gudeg", it is a sweet dish (there is a saying that everything in Yogya is sweet, including the people) made of jack fruit, coconut milk and palm sugar.
Yes, I have been there. Also don't forget to visit Borobudur and Prambanan!