Spanish authorities had little control over much of the territory of Panama. Large sections managed to resist conquest and missionization until very late in the colonial era. Because of this, indigenous people of the area were often referred to as "indios de guerra" (war Indians) who resisted Spanish attempts to conquer them or missionize them.  However, Panama was enormously important to Spain strategically because it was the easiest way to transship silver mined in Peru to Europe.  Silver cargoes were landed at Panama and then taken overland to Portobello or Nombre de Dios on the Caribbean side of the isthmus for further shipment. Asides from the European route, there was also an Asian-American route, which led to traders and adventurers carrying silver from Peru going through Panama to reach Acapulco, Mexico before sailing to Manila, Philippines using the famed Manila Galleons.