Palais Garnier is the single most important Beaux Arts building. It contains two opposite facades as one serves as a formal entrance and the other as a functional entrance. It has a ceremonial entrance way that leads up to a ball room located near the auditorium that was utilized for the Paris Opera House. The building is not complex in terms of its basic outline but it has classical architectural elements, such as the columns that resemble the columns of the Parthenon which also uses variable fluting. The building also has Oil de boeuf windows common in the Baroque period which means “bulls eye”. Compared to the Parthenon, the ornamentation of the building is more modern with extra decorative elements. Unlike the Parthenon which was built from marble, Palais Garnier was constructed with stone and iron.