Antoni Gaudi was a Catalan architect who left an inedible mark with his masterpieces all over Barcelona. Some of his other masterpieces include Sagrada Familia, Park Guell, Casa Mila, etc. Gaudi was inspired by nature, so he refused to use straight lines in any of his work. He loved working on a grand scale, and its best example is Sagrada Familia, which is still under construction even after 135 years.