The Blue Mountains Line is a railway line in New South Wales, Australia, connecting the city of Sydney to the Blue Mountains region. It is part of the Sydney Trains network and serves both suburban and intercity passengers, providing access to popular tourist destinations like Katoomba and Leura. The line features scenic views of the surrounding mountains and valleys, making it a popular choice for travelers. It operates regular services, including express trains, and is known for its historic stations, such as Wentworth Falls and Blackheath, which reflect the area's rich heritage.