branch opened in April 2020. The Royal National Park line, operated by the Sydney Tramway Museum, terminating at Royal National Park railway station. Previously operated as part of the Eastern Suburbs & Illawarra railway line. Goods lines Several railway lines carry goods only: The Metropolitan Goods Railway from Flemington/Sefton to Port Botany, with former branches from Dulwich Hill to Rozelle Yard and from Lilyfield to Sydney Yard via Darling Harbour. The Southern Sydney Freight Line between Macarthur and Sefton, where it connects with the Metropolitan Goods Line. Northern Freight Pass between Thornleigh and Epping turning onto Strathfield line. Closed lines There are several closed lines in Sydney: The Camden Line, from Campbelltown to Camden The Carlingford Line, from Clyde to Carlingford The Potts Hill Line in Potts Hill The Richmond-Kurrajong Line from Richmond to Kurrajong The Rogans Hill Line from Westmead to Rogans Hill The Rookwood Cemetery Line serving Rookwood Cemetery The Ropes Creek Line from St Marys to Ropes Creek The Sandown Line from Rosehill to Sandown. The Warwick Farm Racecourse Line from Warwick Farm to Warwick Farm Racecourse Parts of the Carlingford and Sandown lines will be converted to become a dedicated corridor for the Parramatta Light Rail, most of the Carlingford Line as part of the light rail service, and Sandown Line being used in part to connect it to a light rail depot. Proposed and under construction The following lines are under construction: Parramatta Light Rail between Westmead station and Sydney Olympic Park scheduled to open in stages from 2023 Sydney Metro City & Southwest, the second stage of Sydney Metro network, between Chatswood and Bankstown scheduled to open in 2024. Western Sydney Airport line, between St Marys and Western Sydney Airport. Sydney Metro West, between the Sydney CBD and Westmead via Inner West suburbs. Underground sections Sydney has four underground lines. These sections of railway are extensions of suburban main line commuter services and are not a completely segregated true metro system. The underground sections, especially the City Circle, typically have frequent services. Sydney Metro forms the largest part of Sydney's underground railways and the first subway system in an Australian city. The oldest is the main city loop, the City Circle, which runs between Central, Town Hall, Wynyard, Circular Quay, St James station and Museum stations. Central and Circular Quay are above-ground stations (Circular Quay is elevated, directly underneath the Cahill Expressway), while the