Dom Luis Bridge, Porto. PORTUGAL

The Luís I (or Luiz I) Bridge (Portuguese: Ponte Luís I or Luiz I) is a metal arch bridge that spans the Douro River between the cities of Porto and Vila Nova de Gaia in Portugal. At the time of construction its span of 172 m was the longest on its type in the world. The second photo is the panorama of the Douro seen from this bridge. Photos from 1993