The bridge was built under the order of the Roman Emperor Trajan in 98 A.D. The build did not actually take place until 104-106. His honor is shown by a triumphal arch in the center of the bridge and a small temple at one end. More damage has occurred during wars than during the elements, the Moors destroyed the smallest arch on one side and the second arch on the other side was destroyed by the Spanish to stop the Portuguese. The bridge structure is an arch type. Its function/usage is a road bridge. The location is across the Tagus River in the Caseres Province, Extremadura, Spain. In Spanish it translates to Puente de Alcantara. The main builder of the bridge was Roman arquitect Caius Iulius Lacer. It is built by six archs that stretch a distance of 214 m. They are held up by five pillars and two supports at its ends. 48 m. high at its top, two central archs. Rectangular pillars are about 12,200 m. x 8,300 m. and have triangular detached cut waters of 8,300 m. at the basis and 7 m. each one of its other sides, forming a pentagonal shape. They are directly set on the slate rock that was made flat in order to support ashlars in a right way. The roadway is 8 m. wide: 6,700 ms. for walking space and 1,300 ms. for both little walls. At its center on the roadway there is a one gate Triumphal Arch that has been restored many times. It is 13,15 m. high with a rectangular plan of 11,5 m. x 2,60 m. It is supported by the central pillar of the construction. On it there are two marble plates: on one there is an inscription with the date of construction. At the southern side -left bank of the river- there is a little temple in altis. At its dintel an inscription let us read the architect's name Caius Iulius Lacer and the words "who will live so much as the world would live". At the other side, the northern one, there is another square plan building: the Gold Tower, an instance of the defenses once built. One of the many acts that soured relations between the British and the Spanish during the Peninsula War was the destruction of the Roman Bridge at Alcantara. The bridge was built in 105 A.D. and is known as the Trajan Bridge after the Roman Emperor who reigned then. According to the editor of the Dickson Manuscripts The bridge is made wholly of granite without the use of mortar. Its length is 616 feet; its width 26 feet. The two middle piers are about 190 feet high, and the two middle arches have a span of 150 feet. The usual depth of the water is 37 feet, but in time of flood it sometimes rises in the narrow gorge to a height of 180 feet. The bridge was built to help armies get i and out of Alcantara, and just for regular travel.
A picture of the bridge from a distance.