A railway line that washed into the sea in 2014 will be protected "for generations to come" by a new wall, Rail Minister Chris Heaton-Harris said.
The minister officially opened the first section of the new structure in Dawlish, Devon, on Friday.
The wall forms part of an £80m Network Rail project to safeguard the line which connects Devon and Cornwall with the rest of the rail network.
Repairs to the track, damaged in storms six years ago, cost £40m.
Mr Heaton-Harris said: "Our investment in this new sea wall will provide a resilient railway for generations to come, delivering for the thousands of passengers that rely upon this vital link every day, and the residents whose homes and businesses must be protected."
The first section of the wall protects 360m of railway and homes behind it.
It is 2.5m higher than the 5m wall it replaced and includes a curved top to deflect waves back towards the sea.
It has been designed to preserve views and access to the coast for residents and tourists.
Network Rail route director Mike Gallop said work on finishing touches was progressing well.
He said the new wall "has received lots of positive feedback from the local community and is already better protecting the railway".
Plans for the second phase will see the wall extended by 415m and accessibility improvements at Dawlish station.
This work is expected to start next month and take about two years to complete.
Great Western Railway interim managing director Matthew Golton said: "It is a first stage, but it is a brilliant first stage."