The Dieng Plateau is a volcanic complex in Central Java with several ancient Hindu temples dating back to the 8th century. Located at 2000 m above sea level, it emerged from the ancient eruption of Mountain Prau. The caldera was filled for some time with water, but now it has dried up. Although the place seems quite peaceful, volcanic activity still continues here, and sulphuric poisonous lakes are the evidence of that.
Hindus considered Dieng Plateau a sacred place and built 400 temples here, however, only eight have been preserved. The temples erected by Sanjaya Dynasty were dedicated to Shiva and they somewhat resemble Prambanan architecture. You can also witness Javanese demonic masks being used in architecture as well as marine monsters, which are depicted along the doorways of the temples.
Best time to visit the plateau is during the dry season. Even during the high season from June through August it doesn't get too crowded. The wet season is not a good time to come due to possibility of landslides and flooding.
One of the most precious experiences is the sunrise from the top of Sikunir Hill. Tours usually depart from Yogyakarta right after midnight. The sun rises at about 5 am, so be ready for a cold morning hike, but the views are worth it!