Shāh Abbās Arch (Persian: طاق شاه عباس), is the thinnest arch dam in the world and one of the oldest arch dams in Asia, that has been constructed in Tabas county, South Khorasan Province, Iran. This structure has 700 years old and 60 meters height and 1 meter width crest. Some of Historiographers believe the dam has been built by Shāh Abbās I and some others believe that Shāh Abbās I repaired it.