Dieng Plateau is a marshy plateau that forms the floor of a caldera complex on the Dieng Volcanic Complex in Banjarnegara, Central Java, Indonesia. Referred to as “Dieng” by Indonesians, it sits at 2,000 metres (6,600 ft) above sea level, far from major population centres. The name “Dieng” comes from Di Hyang which means “Abode of the Gods”.
Part of General Sudirman’s guerrilla campaign during the Indonesian War of Independence took place in the area.
With an astonishing elevation of 2,060 m above sea level, Dieng has a distinct subtropical highland climate under the Köppen climate classification (Cwb). In its brief dry season (which is meteorologically aligned with the Southern Hemispherical winter season), there is much less rainfall than in its lengthy monsoon periods (lasting from October to May, also in line with the austral summer). The average annual temperature in Dieng is 14.0 °C. About 2652 mm of precipitation falls annually.
Known for its chilly climate, temperatures may even drop to 2 degrees (along with wind chills down to -2º) in the peak of its dry season. Though infrequent, frosts have been recorded every year, particularly in late evenings and mornings of July and August. This may last for one week in average. Though this regionally-rare weather phenomena occasionally attracts tourists to cluster around the plateau area, it is also notorious for the destruction it often inflicts upon the local produce, with agricultural plants and crops such as potatoes being the most severely affected.
Locals usually call this frost “bun upas”. On the local Javanese dialect, “Bun” (or “embun”) means dew, while “upas” is poison. Although “bun upas” or frost in Dieng is actually not poisonous, this term “upas” was created by local people due to its devastating effect on agricultural plants, in which, the plants die quickly as if as they were poisoned when the frost takes place.
The Plateau is the location of eight small Hindu temples from the Kalingga Kingdom. It is unclear when they were built, estimated to range from mid 7th century to end of 8th century AD; they are the oldest known standing stone structures in Java. They are originally thought to have numbered 400 but only eight remain. The temples are now believed to have been named after the heroes of the Hindu epic Mahabharata.
Michell claims Dieng’s misty location almost 2,093 m above sea level, its poisonous effusions and sulphur-coloured lakes make it a particularly auspicious place for religious tribute. The temples are small shrines built as monuments to the god-ancestors and dedicated to Shiva. The Hindu shrines are miniature cosmic mountains based on plans in Indian religious texts, although Schoppert suggest the design motifs have little connection to India.