2007 $5 Fine Silver Proof Coin, 75th Anniversary of the Sydney Harbour Bridge. Construction of the Sydney Harbour Bridge began in 1924 although there had been calls for a bridge between the city and North Sydney decades earlier. The bridge now carries eight traffic lanes and two rail lines. The arch span is 503 metres and the top is 134 metres above the average sea level. The bridge was opened on 19 March 1932, by the NSW Premier Jack Lang. Struck by the Royal Australian Mint this $5 Proof Coin commemorate the 75th anniversary of the opening. It shows the bridge from below the south pylon. Certificate of Authenticity is included with this coin numbered 1928. Mintage limited to 12,500. Please contact Adelaide Exchange Jewellers to find out more on this item.