Gallery: 200,000 flood Shanghai Expo preview

The Expo doesn’t officially open until May but visitors swamped the Shanghai 2010 Expo grounds this week for the public preview of the largest ever World's Fair.

The Expo staff welcomed the crowds as visitors tested the 2010 Expo facilities and public transportation 10 days before the official 2010 Expo begins.

It’s predicted that up to 100 million people will attend the Expo, which runs from May 1 until October 31, nearly all of them expected to be Chinese.

The China Pavilion was the most popular spot for visitors by far. In addition to the China Pavilion, five theme pavilions, 18 corporate pavilions and the Australia, New Zealand, Luxembourg, Sweden, UK, Pakistan, Saudi Arabia, Italy, and the much talked about U.S. pavilions were also open.

Although people flocked to see the more popular 2010 Expo pavilions, one thing that didn’t quite hold up to the stress was the Expo site’s food services. During the first trial operation day, people found the eating outlets scarce and those that were open were besieged by long queues.

Visitors take pictures of the British Pavilion at the World Expo 2010 site. The British Pavilion has generated an impressive buzz, especially over its most visible feature: the mass of long radiating cilia coating the outside of the building.