25 Ekueles Annobón island

Annobón is a remote volcanic island in the South Atlantic, administered by Equatorial Guinea despite lying far closer to São Tomé and Príncipe. Its inclusion on a circulating denomination is notable given the island's population of roughly 5,000 and its near-total isolation — regular supply ships are infrequent, and the island has historically resisted integration with the mainland government, including an uprising in 1973 that prompted the Macías Nguema regime to forcibly deport a portion of its population.