The Pantheon in Rome is an ancient Roman temple, later converted into a church, renowned for its architectural innovations, particularly its massive concrete dome.

The Roman Pantheon, completed by Emperor Hadrian around 126 AD, is one of the best-preserved ancient Roman buildings. Its original purpose was likely as a temple dedicated to all gods, though its exact function is still debated by historians. Its most striking feature is its unreinforced concrete dome, which remains the largest of its kind in the world. At its apex is the oculus, an open circular hole allowing light and air to enter, symbolically connecting the interior to the heavens. This architectural masterpiece demonstrates advanced Roman engineering and stands as a testament to their sophisticated understanding of materials and construction techniques.