Parque das Nações

This guide to Parque das Nações in Lisbon starts with transatlantic seaplanes landing on this stretch of the Tagus in 1942, then follows the riverbank's decline into refineries, slaughterhouses and toxic dumps once the jet age ended that traffic. It covers Portugal's 1998 decision to stage a world exposition, marking five hundred years since Vasco da Gama's voyage, on the contaminated site nobody else wanted. Look for the single surviving refinery tower on the skyline, left standing on purpose among the pavilions.