In 1992, coinciding with the fifth centenary of the Discovery of the Americas, the Universal Exposition was held for six months in Seville, on the occasion of which the local communications network and urban infrastructure was greatly improved under a 1987 PGOU plan launched by Mayor Manuel del Valle: the SE-30 ring road around the city was completed and new highways were constructed; the new Seville-Santa Justa railway station had opened in 1991, while the Spanish High-Speed Rail system, the "Alta Velocidad Española" (AVE), began to operate between Madrid-Seville. The Seville Airport was expanded with a new terminal building designed by the architect Rafael Moneo, and various other improvements were made. The Alamillo Bridge and the Centenario Bridge, both crossing over the Guadalquivir, also were built for the occasion. Some of the installations remaining at the site after the exposition were converted into the Scientific and Technological Park Cartuja 93.