La Sagrada Família Basilica in Barcelona, Spain

La Sagrada Família,  the most famous building in Barcelona, and a UNESCO world heritage site, will be using over 500T of duplex stainless steel for the completion of the tower structures. Read more here and here

At the time Gaudí designed the Basilica, stainless steel was not invented!

More information on La Sagrada Familia and stainless steel, can be found here.