The Andes region is the most populated region in Colombia. The Andes mountain range is divided in three ranges (cordilleras), separated by the valleys of the Magdalena River and the Cauca River, which are also counted as part of the Andean region.
In the South the three cordilleras are united in the Pasto and Almaguer knots, also known as the Masizo Colombiano, where most important Rivers in Colombia are born. The Cauca River and the Magdalena River are born here and run northwards cutting with their Valleys the Andes in the three cordilleras. Just north of the Cauca Valley, the Western and Central Cordilleras close the middle Cauca into Canyons forming the "Montaña Antioqueña" (The Antioquian Mountain Region), this region and the high snow-topped mountains in the Central Cordillera, just east of the Cauca Valley, form one of the most important coffee growing regions in the world. North of the proper Antioquian Mountain Region is the Paramillo Knot and its three smaller mountain ranges the end the Western Cordilleran into the Caribbean Plains.
The Magdalena Valley is usually divided in the Upper Magdalena, where navigation is scarce, and the Middle Magdalena. At the west of these valleys is the Eastern Cordillera, running from a mountain range in the South separating the Upper Magdalena from the Amazon Basin; the Eastern Cordillera widens into a series of high-plains, where Bogotá, Colombia Capital, lies. A more broken mountain region just North, similar to that on Antioquia, is known as the "Montaña Santanderiana" (Santander Mountain Region). From the Santander Region, the Andes are divided in two ranges, the Perija or Motilones Range in the border with Venezuela, and the Merida Range in Venezuela. Between these ranges the Catatumbo region is shared between Colombia and Venezuela.