Lisbon, Portugal April 1998 Lisbon, the nation’s capital and largest city (estimated population of 650000 people), is located along the west side and near the mouth of the Tagus River estuary (large, dark feature in center of image). The Tagus River estuary is one of the best natural ports on the European continent and can accommodate large ocean going ships. The estuary also has the largest dry dock in the world. The intersecting runways for one of Lisbon’s several airports are visible on a peninsula that extends westerly into the south side of the Tagus River estuary. Two bridges can be seen connecting the eastern shore with the built-up area of Lisbon. With the exception of the alluvial soil deposited by the Tagus River and the irrigated acreage along the delta and floodplain of the river, Portugal is not a country that has an abundance of arable land. The angular-looking field patterns found on the Tagus River delta (near upper right corner) and the circular patterns (center pivot irrigation southeast of the river) show the location and distribution of some of the productive farmland. The greater Lisbon area, including both the city and its suburbs, accounts for most of Portugal’s commerce and much of its industry.