Santa Coloma de Gramanet, called Gramanet del Besós from 1937 until the end of the Spanish Civil War, is a Spanish city and municipality in the province of Barcelona, in Catalonia. It belongs to the Barcelonés region. Santa Coloma de Gramanet is the seventh most populous city in the province of Barcelona, the ninth in Catalonia and the fiftieth in Spain.
Santa Coloma de Gramanet is located to the east of the Besós River, between the Serralada de Marina and the Badalona plateau.
It is bordered to the north by the municipality of Moncada y Reixach, to the south by San Adrián de Besós, to the east by Badalona and to the west by Barcelona. From the Plaza de la Vila de Santa Coloma to the Plaza de Cataluña in Barcelona is only 9 km.
The topography of the municipality is quite rugged. Perpendicular to the river Besós there are three fully or partially urbanized mountain ranges from north to south: the Sierra de San Mateo (which is part of the Sierra de Marina), the Sierra de les Mosques d'Ase (also called Montserrat dels Pobres), and the Sierra d'en Mena. These three mountain ranges form between them two valleys (where their streams used to flow): the Carcereña valley (or Pallaresa valley) and the Sistrells valley.
The highest point of the municipality is the old Iberian village Puig Castellar, with 303 m.