This document describes the construction method of two amazing Structures especially singulars built as part of the International Exhibition Zaragoza 2008. The Tercer Milenio Bridge is world record in bowstring arch with a wide lower deck made on high-strength, self-compacting white concrete (75MPa) to carry road traffic, bicycles and pedestrians. The Pavilion Bridge is a curvaceous complex structure arquitecturally influenced in its design as combined building for exhibitions and footbridge. Both bridges share singular foundations and a complex construction project.