It is 114.69 metres ( 376.28 ft ) wide and 45.55 metres ( 149.44 ft ) high and is built of pale gray travertine stone , with a giant Corinthian columns and a central triangular pediment . Along the roof-line are statues of Christ , John the Baptist , and eleven of the apostles . The faÃ ade designed by Maderno , is 114.69 m wide and 45.55 m high and is built of travertine stone , with a giant order of Corinthian columns and a central pediment rising in front of a tall attic surmounted by statues of Christ , John the Baptist , and eleven of the apostles .