Standing on the bridge we can see the Latin text of Psalms 126 v.1:
nil prosunt vigilum excubiæ nihil arma, minæ que murorum ingentes raucæue tonitrua cannæ 1578 ni deus hancce velis regere ac tutarier irbem.
Nothing avails the guards watch, not weapons, not the threat of massive walls, not the thunder of heavy armoury, if Thou, O God, do not direct and protect this town
The Knox translation is rather different:
Vain is the builder's toil, if the house is not of the Lord's building; vainly the guard keeps watch, if the city has not the Lord for its guardian.