Water Tower and Bridge Pavilion

Bridge Pavilion (Zaha Hadid).....................................Water Tower (Enrique de Teresa)


One of the ironies of world expositions is that while they apparently act as a catalyst for large-scale urban improvements to the host city, the expo sites themselves often end up as ghost towns. Expo architecture always seems to have difficulty finding a second life. Expo Zaragoza, an event whose theme is ‘Water and Sustainable Development’, has done away for the most part with the idea of single-use pavilions. But it has not dispensed with tradition entirely: the Water Tower, an 80-m-high observation post, is probably one of the more monumentally unusable constructions to be undertaken since the building of the Eiffel Tower more than a century ago.

Although over 20 storeys high, the glass and steel structure contains hardly any floors. Except for the base of the building, which houses the Water for Life exhibition, most of its interior is taken up by circulation ramps and empty space. About 3 km of ramps, in fact, are intertwined in a DNA-like double helix: one leading up to the observation lounge and bar, the other descending. Following the teardrop-shaped perimeter of the building, the ramps encircle a tall, airy atrium that, complete with a piece of cheesy corporate sculpture – Splash, by Pere Gifré – would make John Portman proud.

The idea behind the ramps is to facilitate the flow of visitors to and from the observation lounge. In reality, however, many who undertake the hike give up halfway and are forced to descend the up-ramp, making for anything but a smooth flow of pedestrian traffic. The bigger question, however, is what the Water Tower could possibly be used for after the Expo closes and visitor flow turns to a trickle. It would be such an unsustainable shame to have to mothball – or worse, demolish – this urban landmark.


Infrastructure – bridges, canals, roadways, tunnels and the like – has belonged to the discipline of civil engineering since the Enlightenment, whereas representational buildings – such as pavilions, temples and palaces – have been strictly within the purview of architecture. Nary the two shall meet. Until now.

As the name suggests, the Bridge Pavilion is both a piece of public infrastructure and a building for exhibitions. In fact, it bundles the two programmes together: the structure is an enclosed pedestrian bridge that serves as a gateway to Expo Zaragoza from which adjacent and parallel exhibition spaces bifurcate. Although the pedestrian concourse is direct and only slightly curved, the exhibition spaces – especially the larger of the two, spanning two levels – are articulated by means of switchback ramps, carefully positioned windows and finer interior finishes, all aimed at slowing down visitors to a measured pace that is conducive to contemplation.

Supported midway on a small island in the Ebro River, the Bridge Pavilion comprises four interlocking ‘pods’, each diamond-shaped in section. Two pods, arranged linearly on either side of the island, make up the pedestrian concourse while two others, one on either side of the pedestrian pods, contain the exhibition spaces. The intersections of these pods result in the liquid spaces that have become Zaha Hadid’s trademark. Interestingly, it is precisely the public infrastructure component of the Bridge Pavilion that ensures its continued relevance after the closure of Expo Zaragoza. In this regard, the building is a unique example of an expo pavilion that is a genuine urban improvement.

[originally published in Mark Magazine #16]