An archipelago (/ˌɑːrkəˈpɛləɡoʊ/ AR-kə-PEL-ə-goh),[1] sometimes called an island group or island chain, is a chain, cluster, or collection of islands, or sometimes a sea containing a small number of scattered islands. Archipelagos are sometimes defined by political boundaries. For example, while they are geopolitically divided, the San Juan Islands and Gulf Islands geologically form part of a larger Gulf Archipelago.[2]