Expo 2008: Water and Sustainable Development

Expo 2008, themed on the world's dwindling water resources, opened in the Spanish city of Zaragoza on Saturday, days after the riverside site narrowly escaped flooding.

Zaragoza has invested 2.9 billion euros ($4.5 billion) to build the exposition site on the banks of the Ebro River and spruce up the city of 600,000 for the three-month expo. Private sponsors have chipped in another 2 billion euros ($3.12 billion).

Doors to the public open Saturday. Organizers expect 6 million visitors.

The show is the first of a new, scaled-down format of an event formerly known as a universal exposition.

Zaragoza, located halfway between Madrid and Barcelona, chose the theme of water as it is an issue of growing concern to the world and one that constantly stirs debates, and sometimes disputes, in this drought-affected country.

Hundreds were already queuing when Expo opened its gates to the public and Mexican President Felipe Calderon was on hand to open his country's stand during an official visit to Spain.

Ironically, the site was almost flooded last month during Spain's wettest May in decades, provoking a frantic finish to construction that began three years after Zaragoza beat Greek and Italian rivals for the right to host the event.

The first visitors on Saturday crossed from the city to the Expo site via a futuristic bridge, built by Baghdad-born architect Zaha Hadid, across the Ebro, Spain's biggest river.