Surakarta, known colloquially as Solo, is a major city in Central Java, Indonesia. The 46.72 km2 city adjoins Karanganyar Regency and Boyolali Regency to the north, Karanganyar Regency and Sukoharjo Regency to the east and west, and Sukoharjo Regency to the south. On the eastern side of Solo lies Solo River.