25 Sen

Indonesia's early aluminum coinage was a product of acute economic necessity — the newly independent republic lacked both the infrastructure and the hard currency reserves to sustain a bronze or cupro-nickel circulation coinage in the early 1950s. The 25 Sen was struck at the Dutch Royal Mint in Utrecht, a quietly ironic arrangement given that the Netherlands had only formally recognized Indonesian sovereignty in December 1949 after four years of military and diplomatic conflict.