The route of this group of caches brings you over the Royal National Park Line which was a railway from Loftus to the National Park Station between 1886 - 1991.
On Wednesday and Sunday, the Sydney Tram Museum currently runs an electric tram between Loftus and the old Royal National Park station. The trip goes from the museum over the Princes Highway past this railway crossing and two sheds and then to the old railway station platform. See http://www.sydneytramwaymuseum.com.au/ for more details on the tram museum.
When you are here, take notice of the numbers on the label on the side towards the railway line (MNOPQR). There is a sleeper with close to the cache with three digits (STU). This information is needed for the fourth cache in this series.
Did you know that NSW has a geocaching association? Geocaching NSW aims to enhance and improve the activity of geocaching and holds regular events where geocachers meet to enjoy their common interests. Visit the association website here.