A railway line from Avonmouth to Clifton was built in the mid 1850s. Initially operated by a private company, it was taken over by the Great Western/Midland in 1871. At its southern end, near the terminus station of Hotwells, two short tunnels were constructed. The line closed in 1921.
The souuthernmost tunnel was 73 yards long and known as Portway number 1 tunnel. In 1940 it was taken over by Bristol City Council, who used it for archival stotage in World War II. A two level store was built to one side of the tunnel, alongside what became a high corridor. The doors to the separate storage areas were labelled with the owning department - such as ‘City Tresurer’ and ‘Docks Department’