The Ciénaga Grande de Santa Marta (Spanish for Large Marsh of Saint Martha) is the largest of the swampy marshes located in Colombia between the Magdalena River and the Sierra Nevada de Santa Marta. It has an area of 4280 km2 and belongs to the outer delta system of the Madgalena River and is separated from the Caribbean Sea by a narrow, sandy artificial spit built in the 1950s on which is situated coastal route 90 from Barranquilla to Santa Marta.