The Tagus is the longest river in the Iberian Peninsula. It is 1,007 km (626 mi) long, 716 km (445 mi) in Spain, 47 km (29 mi) along the border between Portugal and Spain and 275 km (171 mi) in Portugal, where it empties into the Atlantic Ocean near Lisbon. It drains an area of 80,100 square kilometers (30,927 sq mi) (the second largest in the Iberian peninsula after the...