Colombia is the only country in South America that borders two oceans. However, the strategic importance of the Pacific and Caribbean coasts differs greatly. The hard-to-reach Pacific alluvial plain, lined with mangrove forests, contrasts with the rocky Caribbean coast, which is dotted with bays (picture). The major longitudinal valleys that separate Colombia’s Eastern, Central and Western Cordilleras also open out onto this coastline. The Magdalena Valley was one of the main gateways for the Spanish conquerors. To the east, the river delta is bounded by the Sierra Nevada de Santa Marta, whose northern flank—indented by bays, peninsulas and islands—is constantly eroded by the surf. - Book: Picture 13 – Colombia - 1977