The Solo River is the longest river in the Indonesian island of Java. It is approximately 600 km in length. Apart from its importance as a watercourse to the inhabitants and farmlands of the eastern and northern parts of the island, it is a renowned region in paleoanthropology circles. Many discoveries of early hominid remains have been made at sever…The Solo River is the longest river in the Indonesian island of Java. It is approximately 600 km in length. Apart from its importance as a watercourse to the inhabitants and farmlands of the eastern and northern parts of the island, it is a renowned region in paleoanthropology circles. Many discoveries of early hominid remains have been made at several sites in its valleys, especially at Sangiran, including that of the first early human fossil found outside of Europe, the so-called "Java Man" skull, discovered in 1891.