Work has started to reconnect a Dorset heritage railway with the mainline network to allow passenger services to run for the first time in four decades.
The boundary between Swanage Railway and the old Network Rail line was removed earlier, marking the start of a year-long restoration project.
Railway company chairman Peter Sills described it as a "momentous" event.
It follows the lease of a three-mile (4.8km) stretch of track from Dorset County Council.
The line from Swanage to Wareham was closed by British Rail in 1972.
Swanage Railway volunteers rebuilt a 5.5-mile (8.8km) stretch from Swanage to Norden over 30 years and opened it as a tourist attraction.
Their long-term ambition is to reconnect the 10-mile stretch between Swanage, Corfe Castle and Wareham.
Trial services are planned for 50 days towards the end of 2015 and 90 days in 2016. It is hoped a year-round service will follow.
Earlier, a section of old track at Motala, near Furzebrook, which once marked the boundary between the heritage line and Network Rail, was replaced.
Previously, any unauthorised trains crossing from one section to the other would have derailed.
Two gates across the track and a shelter hut have also been removed.
Tony Udall, a Swanage Railway volunteer for more than 30 years, said: "Although I hoped this moment would come, I was less sure about whether I would be alive to see it."
Mr Sills said the removal of the boundary was the culmination of many years of hard work.
"In the long term, it will enable people, once again, to take a day trip from Swanage to London," he said.
Further upgrade work will include replacing 1,700 sleepers and repairing bridges, fences and embankments.