Estremadura (əshtrəmədōˈrə) [key], region, W Portugal, formerly a province, now divided between the provinces of Estremadura and Ribatejo, with a small part in Beira Litoral. Estremadura province consists of S Leira, N Setúbal, and most of Lisboa districts. The capital of the province is Lisbon. Wide plains flank the fertile and heavily wooded Tagus River valley. There are grainfields, orchards, and vineyards; copper, iron, marble, coal, and salt are found in the province. Fishing is important along the coast.