Between the rue César Caire and boulevard Malesherbes in Paris lies a rather unique church. Completed in 1871, the Église Saint-Augustin was built when Baron Haussmann was renovating the streets of Paris during the Second French Empire. At 91m long and 73m wide, this was the first building of its size to be made from an iron and steel frame. Famous architect Victor Baltard designed the church, which was inspired by Romanesque and Byzantine styles. With the site being triangular, the transept being octagonal, and the roof covered by a dome, this church truly plays with geometry. With its stunning sculptures, intricate paintings, and lovely frieze of Christ with his apostles, this church is certainly worth the trip.