There still is a debate whether the islands were or were not seen by some of the early European discoverers in the 16th century. Historians take note of the early navigational routes of European explorers in the Pacific. There is disagreement as to whether Spaniard Ruy López de Villalobos, who landed in several Caroline Islands, spotted the Palau archipelago in 1543. No conclusive evidence exists, but some believe he could have seen the tip of a southernmost island in the group.