The Pantheon in Rome is an stunning example of architectural prowess and stunning feats of construction. It was built from 113-125 AD and acts as a former Roman temple and Catholic church, dedicated to St. Mary and the Martyrs. The impressive structure is round in plan, with a portico of large granite Corinthian columns and its famous, world's largest unreinforced concrete dome. Internally it is 43 metres (142 feet) tall and 43 metres in diameter, making for a truly awe inspiring spectacle. The incredible building still stands today and is visited by over 6 million people each year.