"The Aqueduct of Segovia (or more precisely, the aqueduct bridge) is one of the most significant and best-preserved monuments left by the Romans on the Iberian Peninsula. It is among the most important symbols of Segovia, as is evidenced by its presence on the city's coat of arms.
As it lacks a legible inscription (one was apparently located in aqueduct's attic, or top portion), the date of construction cannot be definitively determined. Researchers have placed it between the second half of the 1st Century AD and the early years of the 2nd Century.
The first section of the aqueduct contains 36 pointed arches, rebuilt in the 15th Century to restore a portion destroyed by Moors in 1072. The line of arches is organized in two levels, decorated simply, in which predominantly simple moulds hold the frame and provide support to the structure.
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, mainly to the Segovia Alcázar, until recently. During the 20th Century, the aqueduct suffered wear and tear due to pollution from heaters and automobiles. The latter used to pass below the arches. Natural erosion from the granite itself has also affected the structure through the years. Contrary to popular belief, vibrations caused by traffic do not affect the aqueduct due to its great mass." - in: wikipedia.