The Bargo River Viaduct, completed in 1919, is a heritage-listed brick arch railway bridge spanning the Bargo River in Tahmoor, New South Wales. Designed by the New South Wales Government Railways during the Main South Line duplication, it exemplifies early 20th-century engineering and the era’s emphasis on local materials, with bricks sourced from the State Brickworks at Homebush. The viaduct comprises multiple arches, each with a 15.2-metre clear span, and extends 76 metres in total length. Set amidst native bushland, the surrounding area offers a tranquil setting for walking, picnicking, and nature appreciation. Recognised for its historical and aesthetic significance, the viaduct was added to the New South Wales State Heritage Register in 1999. Easily accessible from Sydney, the Bargo River Viaduct is approximately 1 hour and 15 minutes by car.