The Port of Holyhead's breakwater has been closed by Stena after recent storms have left it too unsafe for public access.
The historic breakwater - that protects Holyhead port - has been badly hit by Storm Arwen and Storm Barra.
It means owner Stena Line Ports has to restrict access as it assesses the damage.
A spokesman said: "Stena Line Ports regrets to inform the public that storm damage has forced the closure of Holyhead’s Breakwater.
"Storm Arwen and Storm Barra have resulted in areas of the historic breakwater being too unsafe for public access.
To read more on the breakwater built between 1848 and 1873, North Wales Live reports.