There are (at least) two sets of ABC Islands:
Caribbean
In the Leeward Antilles, the southerly islands of the Lesser Antilles:
- __A__ruba - an autonomous dependency of the Kingdom of the Netherlands
- __B__onaire - a "special municipality" of the Netherlands
- __C__uraçao - an autonomous dependency of the Kingdom of the Netherlands
United States of America
In the Alexander Archipelago, in Southeastern Alaska:
- __A__dmiralty Island
- __B__aranof (also Baranov or Sitka) Island - largest city: Sitka
- __C__hichagof Island