Plus ultra (/ˌplʊs ˈʊltrɑː/, Latin: [ˈpluːs ˈʊltraː], Spanish: [plus ˈultɾa]; Latin meaning "further beyond"; in Spanish, más allá) is the national motto of Spain. It is adopted from the personal motto of Charles I of Spain who was also Charles V, Holy Roman Emperor, and is derived from the opposite Latin original Non plus ultra, which means "Not[hing] further beyond". While "Plus ultra" refers to the political ambition of world power after the European discovery of the Americas by Christopher Columbus, "Non plus ultra" got the meaning of "Nothing better" (top notch, unbeatable) in a common sense.
According to Earl Rosenthal, author of The Palace of Charles V in Granada (1985), the motto is closely associated with the Pillars of Hercules, which, according to Greek mythology, were built by Hercules near the Straits of Gibraltar to mark the edge of the then known world. According to mythology the pillars bore the warning Nec plus ultra (also Non plus ultra, "nothing farther beyond"), serving as a warning to sailors and navigators to go no farther.