The Sultan Iskandar Building or Bangunan Sultan Iskandar (BSI) (Jawi: باڠونن سلطان إسکندر) is the largest customs, immigration and quarantine (CIQ) in Malaysia. Located at Bukit Chagar, Johor Bahru, Johor at the former site of the Lumba Kuda flats, Kampung Bukit Chagar, and recreation park, it occupies an area of 232,237 square metres (2,499,780 sq ft). This building is part of the Southern Integrated Gateway project was named after the late Sultan of Johor, Almarhum Sultan Iskandar.