There were two major projects to build  this bridge. The first was in 1735 , which  had a 35 meter arch. The works lasted only 8 months, but was a bit of a failure because six years later it collapsed, causing the death of  50 people!  They had another go in 1751 and ended in May 1793 with a 98 metre high masterpiece, built of stone blocks taken from the bottom of the Tagus gorge below.