Pasir Panjang PillboxPasir Panjang Pillbox is a strengthened-concrete defensive structure from World War II, located in Pasir Panjang in the southwestern area of Singapore.Background and historyIn advance of the Japanese invasion of Malaya and Singapore between 1941 and 1942 during World War II, a number of concrete-built defensive pillboxes were built along Singapore's eastern and western coasts.