Antioquia Department in the context of "Atrato River"

Medellín (/ˌmɛdeɪˈ(j)iːn/ MED-ay-(Y)EEN; Spanish: [meðeˈʝin] or [meðeˈʎin]), officially the Special District of Science, Technology and Innovation of Medellín (Spanish: Distrito Especial de Ciencia, Tecnología e Innovación de Medellín), is the second-largest city in Colombia after Bogotá, and the capital of the department of Antioquia. It is located in the Aburrá Valley, a central region of the Andes Mountains, in northwestern South America. The city's population was 2,427,129 at the 2018 census. The metro area of Medellín is the second-largest urban agglomeration in Colombia in terms of population and economy, with more than 4 million people.

In 1616, the Spaniard Francisco de Herrera Campuzano erected a small indigenous village (poblado) known as "Saint Lawrence of Aburrá" (San Lorenzo de Aburrá), located in the present-day El Poblado commune. On 2 November 1675, the queen consort Mariana of Austria founded the "Town of Our Lady of Candelaria of Medellín" (Villa de Nuestra Señora de la Candelaria de Medellín) in the Aná region, which today corresponds to the center of the city (east-central zone) and first describes the region as "Medellín". In 1826, the city was named the capital of the Department of Antioquia by the National Congress of the nascent Republic of Gran Colombia, comprising present-day Colombia, Venezuela, Ecuador, and Panama. After Colombia won its independence from Spain, Medellín became the capital of the Federal State of Antioquia until 1888, with the proclamation of the Colombian Constitution of 1886. During the 19th century, Medellín was a dynamic commercial center, first exporting gold, then producing and exporting coffee.

Aburrá Valley (in Spanish Valle de Aburrá), is the natural river basin of the Medellín River and one of the most populous valleys of Colombia in its Andean Region with near 4 million inhabitants in its biggest urban agglomeration: The Metropolitan Area of the Aburrá Valley. The valley is located on the Central Range, over the Antioquian Mountain just between the Magdalena and Cauca valleys from east to west. The name "Aburrá" comes from an ancient language spoken in the place by the "Aburreans" (Aburraes) before the Spaniards settled the place during the 16th century.

The valley is oriented from south to north being the south the highest level and the north the low level. The altitudes of the mountains around the valley (west and east mountains), can reach up to 3,100 m (10,200 ft) above the sea level (Padre Amaya Peak). The lowest level is 1,300 m (4,300 ft) above sea level. From its north natural limit to its southern part, the valley is 60 km (37 mi) long, while there are several varieties in its width being the wider part the one that corresponds to the municipality of Medellín with 8–10 km (5.0–6.2 mi) and the narrowest the part that corresponds to the municipality of Copacabana with 3 km (1.9 mi).

The Metropolitan Area of the Aburrá Valley (Spanish: Área Metropolitana del Valle de Aburrá) is the second most important and populated metropolitan area in Colombia. The region is made up of ten municipalities, Medellín being the most important, largest and the capital city of the Antioquia Department.

Sinú River (Spanish: Río Sinú), is a river in northwestern Colombia that flows mostly through the Córdoba Department and into the Caribbean. It is the third most important river in the Caribbean Region, after the Magdalena River and the Cauca River. It is born in the Antioquia Department, flowing south to north for 415 kilometres (258 mi) until flowing into the Caribbean Sea. The river is navigable for only half of its length, 200 kilometres (120 mi) starting in Montería, the largest city in its basin. Also, this river is the main tourist attraction of Montería decorated with the first avenue when it passes by Montería.

The river flows between the eastern and middle prongs of the Cordillera Occidental.

Bolívar (Spanish pronunciation: [boˈliβaɾ]) is a department of Colombia. It was named after one of the original nine states of the United States of Colombia. It is located to the north of the country, extending roughly north–south from the Caribbean coast at Cartagena near the mouth of the Magdalena River, then south along the river to a border with Antioquia Department. The departments of Sucre and Córdoba are located to the west, and Atlántico Department to the north and east (most of the border formed by the Canal del Dique). Across the Magdalena River to the east is Magdalena Department. The flag of the department bears a resemblance to the flag of Lithuania.

Its capital is Cartagena de Indias. Other important cities include Magangué, El Carmen de Bolívar and Turbaco.

Santander (Spanish pronunciation: [santanˈdeɾ]) is a department of Colombia. Santander inherited the name of one of the nine original states of the United States of Colombia. It is located in the central northern part of the country, borders the Magdalena River to the east, Boyacá to the south and southeast, the Norte de Santander Department to the northeast, the Cesar Department to the north, the Bolivar and Antioquia Departments to the west. Its capital is the city of Bucaramanga.

Turbo is a port city in Antioquia Department, Colombia. Part of the Urabá Antioquia sub-region, it is located on the coast of Gulf of Urabá, 340 km north of Medellín (the department capital and second largest city). Serving as the capital of the Urabá region within Antioquia. Historically, the area now known as Turbo was once called Pisisi, but the name Turbo was in use by 1741. On May 11, 1839, the central government allocated one thousand pesos for the construction of military service barracks in Turbo. In 1840, the republican president assigned one thousand fanegas of uncultivated lands for the new population. Turbo was officially established as a municipality in 1847.

Turbo lies near the southeastern tip of the Darién Gap and is the northern terminus of the main route of the Pan-American Highway in South America. There is currently no paved road connecting through the region to Yaviza, Panama, where the highway continues through Central and North America.

The Cordillera Occidental (English: Western Ranges) is the lowest in elevation of the three branches of the Colombian Andes. The average altitude is 2,000 m (6,600 ft) and the highest peak is Cerro Tatamá at 4,100 m (13,500 ft). The range extends from south to north dividing from the Colombian Massif in Nariño Department, passes north through Cauca, Valle del Cauca, Risaralda, Chocó, and Caldas Departments to the Paramillo Massif in Antioquia and Córdoba Departments. The cordillera is paralleled on the east by the Cauca river. From this massif the range divides further to form the Serranías de Ayapel, San Jerónimo and Abibe. Only to recede into the Caribbean plain and the Sinú River valley.

It is a direct continuation of Cordillera Occidental of Ecuador.