The memorial built into the churchyard wall of St Nicholas' Collegiate Church, facing Market Street is the famous Lynch Memorial Window.
It commemorates a grim 1493 legend where the Mayor of Galway, James Lynch FitzStephen, personally hanged his own son Walter from their home window after he confessed to murdering a visitor from Spain.
The Spanish young man was their house guest. Perhaps out of jealousy, Walter suspected that he was trying to steal his girlfriend from him, and stabbed him to death.
Torn between his duty as a judge and his love as a father, James Lynch sentenced his son to death.
When a massive crowd rioted to prevent the local executioner from carrying out the sentence, the Mayor executed his son himself from his own window overlooking Market Street.
He subsequently retired into complete public seclusion out of grief.
After his house had been vacant for a long time, some locals dismantled the front facade including that very window and built it on the pavement in front of this church on Market Street.
This act of "stern and unbending justice" is widely cited in local lore as a fictionalized origin of the term "lynching".