What Greek and Roman elements are combined in the Pantheon?

The Pantheon, rebuilt by the emperor Hadrian, is a masterpiece of Roman architecture that artfully synthesizes traditional Greek and Roman design elements.123

The building combines these influences in the following ways:

• Greek Elements: The front of the structure features a traditional Classical porch, characterized by a rectangular design with a gabled roof supported by Corinthian columns and a triangular pediment.13
• Roman Elements: Behind this conventional facade lies a distinctly Roman, circular cella or rotunda. This immense interior space is constructed of concrete and capped by a massive concrete dome—a hallmark of Roman engineering prowess. The dome features an oculus, a 27-foot-wide opening at its center that serves as the primary light source for the interior.132

While the exterior maintains the appearance of a traditional rectangular temple, the revolutionary design prioritizes the vast, circular interior space, marking a significant departure from earlier architectural norms.1