Batam refers to both an island, municipality (an Indonesian kotamadya), the largest city in the Riau Islands Province of Indonesia, across the Strait of Singapore, the third-largest city in Sumatra region after Medan and Palembang, and the eighth-largest city in Indonesia after Jakarta Raya, Surabaya, Bandung, Medan, Semarang, Makassar, and Palembang.
Batam is an industrial boomtown, an emerging transport hub, a part of a free trade zone the Indonesia–Malaysia–Singapore Growth Triangle, located 20 km (12 mi) off Singapore’s south coast. The 715-km2 (276-mi2) island, now just barely smaller in sizes to Singapore due to the latter’s reclamation, is the core part of the municipality, of which 450 km2 is classified as urban. Batam’s 2,200 km2 municipality (administratively) covers a number of scattered islands and islets, with Galang and Rempang islands to the immediate south connected to Batam by short bridges, collectively called Barelang with these two islands maintaining their rural character. Bulan Island is also rural. The municipality has a population of 1,035,280 (prediction in May 2015)., also It is the closest part of Indonesia to Singapore, at a minimum land distance of 5.8 km, similar in length to the Transbay Tube. As per the 2010 Census, it was the fastest-growing municipality in the nation, with a population growth rate of 11% per year.