Pematangsiantar (sometimes written as Pematang Siantar, acronym PT. Siantar or P. Siantar, colloquially just Siantar but the official name has no space) is an independent city in North Sumatera, Indonesia, surrounded by, but not part of, the Simalungun Regency. Pematangsiantar formerly had the status of a second level district (daerah tingkat dua) and has been elevated to Kota - its population was 219,319 in 1990 Census, 242,756 in 2000 Census, and 229,525 in the 2005 Intercensal count.