Sangiran

Sangiran is a dome of Javanese farmland that tectonic uplift pushed up and erosion then cut open. About 7 by 8 kilometres across, it sits in the Solo River valley 15 kilometres north of Surakarta, and its exposed beds run from the upper Pliocene to the end of the Middle Pleistocene, a record UNESCO describes as covering the last 2.4 million years. Erosion did the first digging. UNESCO credits natural erosion and transport as the most efficient excavators the site has ever had, and the same processes break up most finds before anyone reaches them.

Eugène Dubois tried here first, in 1883, found little of interest and moved east to Trinil, where he made his name with Java Man. Ralph von Koenigswald came in 1934. Excavations between 1936 and 1941 produced the site's first hominid fossil, and the finds kept coming: Pithecanthropus erectus, since folded into Homo erectus, and the puzzling heavy-jawed material known as Meganthropus. UNESCO now counts more than 100 individuals of Homo erectus from these layers, the oldest at least 1.5 million years old, along with the stone flakes of the Sangiran industry and occupation floors about 1.2 million years old. A 1995 UNESCO report ranked Sangiran with Zhoukoudian, Olduvai Gorge, Sterkfontein and Willandra Lakes, and called it more fruitful in finds than any of them.

Indonesia protected 56 square kilometres around the dome in 1977, and UNESCO listed the Sangiran Early Man Site in 1996. For decades villagers who farmed the slopes also dug fossils and sold them to local buyers. A 1992 cultural heritage law tightened control, though the illegal trade never fully stopped, and in 2010 an American who claimed to be a scientist was arrested near Sangiran with a truck of fossils in boxes and sacks.

The museum's current building at Krikilan opened in December 2011 as the first of four planned clusters: Ngebung for the history of discovery, Bukuran for the human fossils and Dayu for the newest research. Museum head Harry Widianto told the Jakarta Post in 2012 that Krikilan was the most important of the four. Its halls hold dioramas of Sangiran about a million years ago, with Mount Lawu behind and people and animals in front, several of them drawing on the work of the sculptor Elisabeth Daynes. The road runs north from Surakarta towards Purwodadi, and the turnoff past Kalioso winds about 4 kilometres through villages to the visitor centre.