A methodological approach for sustainable conservation and protection of historical timber bridges by encouraging their recognition as a world heritage site

Timber bridges represented important works for every civilization in all historical periods, from prehistory to the early Middle Ages, from classical Rome to the European Enlightenment, passing through China, Japan, and Southeast Asia. These artifacts played an important role in the history of human development; the architectural complexities and structural typologies are numerous and often diversified by geographical area and historical period, beyond the classic picturesque evocations. Many of them could rightfully become part of the World Heritage List, due to their exceptional character and uniqueness in terms of design, materials, workmanship or setting, as well as by virtue of the intangible values they still possess. However, these works, apart from those already universally recognized and protected, are underestimated, forgotten, or not protected and preserved in the best way. The paper, after an overview of the main historical testimonies of timber bridges, provides methodological and operational indications for studying and cataloguing these artifacts, by considering any architectural, urban and vulnerability aspects, to create a rich database and propose to activate shared protection to the national and international authorities.