The Mira River () is a
Portuguese river
A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...
in southwestern
Alentejo
Alentejo ( , , ) is a geographical, historical, and cultural region of south–central and southern Portugal. In Portuguese, its name means "beyond the Tagus" ().
Alentejo includes the regions of Alto Alentejo Province, Alto Alentejo and Bai ...
. It is long.
It has its sources on the northern slopes of the
Serra do Caldeirão and pursues a southeast–northwest course with a generally mild inclination to the
Atlantic Ocean
The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...
, where it discharges through a small calm delta near the town of
Vila Nova de Milfontes, south of
Lisbon
Lisbon ( ; ) is the capital and largest city of Portugal, with an estimated population of 567,131, as of 2023, within its administrative limits and 3,028,000 within the Lisbon Metropolitan Area, metropolis, as of 2025. Lisbon is mainlan ...
. It is one of the two only rivers in Portugal with a chiefly south–north orientation (the other being its neighbour
Sado) and one of the few rivers in
Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
with this orientation.
Mira basin borders Sado River basin at north and
Guadiana River
The Guadiana River ( , , , ) is an international river defining a long stretch of the Portugal-Spain border, separating Extremadura and Andalusia (Spain) from Alentejo and Algarve (Portugal). The river's basin extends from la Mancha and the ea ...
basin eastwards.
Main tributaries in the right bank: Torgal Rivulet, Luzianes River and Perna Seca River. Main tributaries in the left bank include rivers Macheira, Guilherme and Telhares.
Distributary streamlines run perpendicularly along the coastline and discharge directly to the Atlantic Ocean.
Since its name origins are prior to Roman dominion in the zone, it is believed, that the name ''Mira'' may have the same Celtic or pre-Celtic origin of that of the old city of
Miróbriga
''Mirobriga'' or ''Mirobriga of the Celts'' (''Mirobrigensis qui celtici cognominantur - Plin. Nat. IV 118'') was an ancient town in the westernmost part of Lusitania during the Iron Age and Roman Times that was mentioned by Pliny the Elder and ...
(cradle of the modern city of
Santiago do Cacém
Santiago do Cacém () is a municipality in Setúbal District in Portugal. The population in 2011 was 29,749, in an area of 1059.69 km2.
The present mayor is Álvaro Beijinha, elected by the Unitary Democratic Coalition. The municipal holiday ...
), the ruins of which lie to the north. It is known that in the pantheon of the local tribes (called Celtici by the Romans) there was a god for whom devotion was made to protect the waters, whose name was ''Mirobieus''.
External links
Maps and data at the National Information System for Hydric Resources''(in Portuguese)''
Rivers of Portugal
{{Portugal-river-stub