remainder are below ground. The line to St. James station and Museum was opened in 1926, but Circular Quay was a "missing link" until 1956. The "western limb" of the City Circle through Town Hall and Wynyard to Sydney Harbour Bridge opened in 1932, in conjunction with the opening of the Sydney Harbour Bridge. The second, the Eastern Suburbs line, opened in 1979. It runs between Redfern, Central, Town Hall, Martin Place, Kings Cross, Edgecliff, Woollahra (Unused Platforms) and Bondi Junction stations. All these are underground, but there are three above-ground sections, two on viaduct and one in cutting. Most of the platforms at Redfern and Central stations are above ground, including the platforms for the City Circle, but the Eastern Suburbs line is underground. At the time of its construction, the line had been intended to finish at Kingsford but it was curtailed at Bondi Junction for political and financial reasons. In the late 1990s, there were plans to extend the line to Bondi Beach, but these have since fallen through. The third underground line is the Airport Line, which opened in 2000, prior to the Sydney Olympics. This serves Central, Green Square, Mascot, Domestic Airport (underneath the Domestic terminals), International Airport (underneath International terminal at Sydney Airport), and Wolli Creek. After Wolli Creek it joins the above-ground East Hills line at Turrella. The fourth underground line is the Epping to Chatswood rail link, opened in 2009. It links Chatswood to Epping, with new underground platforms at Epping and new underground stations at Macquarie University, Macquarie Park and North Ryde. The line was intended to continue from Epping to Parramatta, incorporating the existing Carlingford line, but this section was postponed during the railway's construction because of financial reasons. A stub tunnel was constructed at the northern end of Epping station in the event that work on the remainder of the line ever resumed. In 2019, the Epping to Chatswood railway was incorporated into the new Northwest Metro, which involved converting the line's commuter rail configuration to a rapid transit system. This ended the possibility of extending the railway to Parramatta as a commuter rail line. Disused tunnels Sydney has several disused tunnels. The best known of these are those leading out of St James station. There are also several disused tunnels and platforms on the Eastern Suburbs line, which like St James station provided for the possibility of four