Palau was originally settled between the 3rd and 2nd millennia BCE, most likely from the Philippines or Indonesia. Sonsorol, part of the Southwest Islands, an island chain approximately  from the main island chain of Palau, was sighted by the Spanish as early as 1522, when the Spanish mission of the ''Trinidad'', the flagship of Ferdinand Magellan's voyage of circumnavigation, sighted two small islands around the 5th parallel north, naming them "San Juan".