Abstract: Scattered throughout the British Isles are approximately 200 surviving iron bridges and aqueducts dating from the 1770's to the 1850's. The first generation of civil engineers creating Britain's transportation system were using an improved iron that had been developed in Britain during the 18th century whose tensile strength and suitability for making cast iron revolutionized how bridges were built. Virtually all such bridges occur only in the British Isles and were built within that short time period because the momentum of innovation in iron processing that had made them possible moved on to develop steel for their successors.
This paper touches on their origins, their variety, the challenges of finding them, and their historic significance. In order to assure their preservation and to facilitate further research, these survivors need to be comprehensively inventoried, visited, photographed, their historical information documented, and their GPS coordinates taken with the resulting data computerized for ease of access, sharing, and updating.