The T4 Eastern Suburbs and Illawarra Line is a commuter rail service in Sydney, Australia. It connects the eastern suburbs of Sydney to the Illawarra region, running from Bondi Junction to Cronulla and Waterfall. The line serves key stations, including Central, Wollongong, and Sutherland, providing access to various residential and commercial areas. This line is part of the Sydney Trains network and operates frequent services throughout the day. It plays a crucial role in facilitating travel for residents and visitors, linking them to major attractions, workplaces, and transport hubs in the region.