 There are many islands of Costa Rica, the most remote being Cocos Island and the largest being Isla Calero.The nation's coastal plain separated by the Cordillera Central and the Cordillera de Talamanca, which form the spine of the country and separate the Pacific and Caribbean drainage divides.The Cordillera de Guanacaste is in the north near the border with Nicaragua and forms part of the Continental Divide of the Americas.