Roman bridge of Córdoba, Spain © Jeremy Woodhouse/Getty Images

The Roman bridge of Córdoba, in the ancient Spanish city’s historic center, has been rebuilt several times over the centuries. For 2,000 years it was the city’s only bridge across the Guadalquivir River, originally built in the first century BCE during the expansion of the Roman Empire. Much of the current bridge dates from reconstruction in the 8th century following the Moorish conquest, a period when hundreds of mosques and palaces were built, and Córdoba became one of Europe"s largest cities and a center of learning and culture.