Galway City Council has closed off a popular area by the River Corrib, after large crowds gathered there in recent days.
The local authority said that gardaí had requested that the so-called 'Middle Arch' be fenced off, in the interests of public health.
The pier, between Wolfe Tone Bridge and Claddagh Quay, is a popular location for locals to gather during fine weather.
City council crews blocked access to the area this morning. It will remain closed for a number of weeks.
Similar measures were imposed last September, after several hundred students congregated around the river, at the start of the academic year.
Following that incident, barriers were in place around the pier for several months.
