The world's most unusual circular bridge

The Laguna Bridge is a unique example of circular bridge design that slows down traffic and reduces impact on the ecosystem.

The Laguna Bridge consists of two semicircles, each one-way and supported by concrete piers. The engineers' goal was to allow drivers to drive smoothly across the lagoon instead of using motorized rafts as they did in the past. The bridge was designed by Rafael Viñoly Architects , the firm behind many famous structures around the world, including the 432 Park Avenue skyscraper in New York, the Japan National Stadium in Tokyo, and the Walkie Talkie building at 20 Fenchurch Street in London, according to IFL Science .

Laguna Bridge seen from above. (Photo: CYD Ingenieros).

According to Dezeen, the bridge over the lagoon cost $10 million to build, and was constructed from more than 450 tonnes of steel, 40km of prestressed cables and 3,500m3 of concrete. The bridge was completed in 2014, a year after construction began.

At first glance, the shape of the bridge might seem unnecessary, but the architecture firm designed the structure with a few specific goals in mind. First, the Garzón Lagoon is one of 22 places in Uruguay designated as Important Bird Biodiversity Areas, home to Chilean flamingos, plovers, and endangered amphibians like Darwin's toads. Therefore, creating a bridge that would have as little impact on the surrounding ecosystem and waters as possible was important.

'By separating the two routes on the circular bridge, the design reduces the time spent at any point on the water in continuous shadow as the Sun moves across the sky and minimizes the adjacent area affected by shade, improving the penetration and dispersion of light throughout the water column , ' Rafael Viñoly Architects explains.

The bridge is also designed to slow people down in both directions. The structure's tight curve radius forces motor vehicles to slow significantly as they cross the bridge, encouraging drivers to take in the natural beauty of the area.

Pedestrian walkways on either side of the traffic lanes provide access to the central opening of the bridge and its perimeter, where visitors can sit down to fish and enjoy the view.