It was extensively renovated in time for the 2004 Summer Olympics and the 2004 Summer Paralympics , including a roof designed by Santiago Calatrava , and innovatively positioned with Enerpac hydraulics . The roof was added atop the sidelines and completed just in time for the opening of the Games . The stadium was then officially re-opened on 30 July 2004 . It hosted the athletics events and the football finals at the Olympics and the athletics at the Paralympics . It also hosted the opening ceremony on 13 August 2004 , and the closing ceremony on 29 August 2004 along the paralympics ceremonies on 17 and 28 September . In 2007 , OAKA Stadium hosted the 2007 UEFA Champions League Final between AC Milan and Liverpool ( 2-1 ) . The stadium 's attendance was reduced to 72,000 for the Olympics , the initial capacity was some 75,000 , though only 69,618 seats were made publicly available for the track and field events and slightly more for the football final . The turf system consists of natural grass in modular containers which incorporate irrigation and drainage systems
opening ceremony
2004 Summer Olympics opening ceremony
Olympic Stadium (Athens)