One of my favorite pavilions, inside and out, is the United Arab Emirates site. It should be on everyone's Expo "must see" list simply because it is a structure designed by renowned architectural firm Foster + Partners, however the pavilion is much richer than just the exterior. Their team did a beautiful job integrating the new with the old, the synthetic and the natural. I think this shot captures that; the walls are constructed to represent their natural landscape of large red sand deserts, while you can faintly see the sleek, modern pillars used as part of their exhibit.
The experience inside the UAE pavilion is superb; from 3-D imaging and integration with their pavilion smart phone app, to an enthralling film, and gallery all about the date palm. The narrative of their exhibit addresses the rapid growth of the country, the consequences it has had on natural resources, and what their two major cities are trying to do about it. It's a compelling visit and worth the wait to see it.