Don Pedro Mesa, the prior of the nearby Jerónimos del Parral monastery, led the project. A total of 36 arches were rebuilt, with great care taken not to change any of the original work or style. Later, in the 16th century, the central niches and above-mentioned statues were placed on the structure. On 4 December, the day of Saint Barbara, who is the patron saint of artillery, the cadets of the local military academy drape the image of the Virgen de la Fuencisla in a flag. The aqueduct is the city's most important architectural landmark. It had been kept functioning throughout the centuries and preserved in excellent condition. It provided water to Segovia until the mid 19th century. Because of differential decay of stone blocks, water leakage from the upper viaduct, and pollution that caused the granite ashlar masonry to deteriorate and crack, the site was listed in the 2006 World Monuments Watch by the World Monuments Fund (WMF). Contrary to popular belief, vibrations caused by traffic that used to pass under the arches did not affect the aqueduct due to its great mass. WMF Spain brought together the Ministry of Culture, the regional government of Castilla y León, and other local institutions to collaborate in implementing the project, and provided assistance through the global financial services company American Express. One of the buildings of Segovia's former mint, the "Real Casa de Moneda", houses an aqueduct interpretation centre, developed with funding from European Economic Area grants. There is a connection between the mint and the aqueduct in that coins minted in Segovia used the aqueduct as a mint mark. Another link is that the 16th-century building harnessed water power to drive its machinery, although the water is taken directly from the River Eresma rather than sourced from the aqueduct.