sentences:  The region is traversed by a number of rivers heading from the Andean highlands to the sea, including Colombia's principal river, the Magdalena, which disgorges at the main port of Barranquilla.As the area first settled by Europeans, the Caribbean region is also the location of the historic port cities of Santa Marta and Cartagena.However, whilst generally low-lying and humid, the region also includes the Sierra Nevada de Santa Marta mountain range and the Guajira Desert.