The Sydney Metro is a fully automated rapid transit system serving the city of Sydney, New South Wales. Currently consisting of one line that opened on 26 May 2019, it runs from Tallawong to Chatswood and consists of 13 stations and 36 km (22.4 mi) of twin tracks, mostly underground. Work is progressing to extend this line from Chatswood to Bankstown, running under Sydney Harbour and the Sydney Central Business District (CBD) with a scheduled 2024 completion. When completed, this line will have 66 km (41.0 mi) of twin tracks and 31 stations. Two additional lines have been announced; Sydney Metro Western Sydney Airport and Sydney Metro West. Sydney Metro Western Sydney Airport will run approximately 23 km from St Marys to the planned Aerotropolis Core.