Dams
Strait in Darius time
Hydrolic system in Shushtar
Observatory
Astrolabe
coinage
Building and Sailing Iranian Lenj Boats
Iranian Lenj vessels are traditionally hand-built and are used by inhabitants of the northern coast of the Persian Gulf for sea journeys, trading, fishing and pearl diving. The traditional knowledge surrounding Lenjes includes oral literature, performing arts and festivals, in addition to the sailing and navigation techniques and terminology and weather forecasting that are closely associated with sailing, and the skills of wooden boat-building itself. The navigational knowledge used to sail Lenjes was traditionally passed on from father to son. Iranian navigators could locate the ship according to the positions of the sun, moon and stars; they used special formulae to calculate latitudes and longitudes, as well as water depth.