On the feastday of Corpus Christi, monks would say prayers in a procession to St. Paul's Cathedral. They set off from Paternoster Row chanting the Lord's Prayer (Pater noster... being the opening line in Latin). They would reach the final 'amen' as they turned the corner in Ave Maria Lane, after which they would chant Hail Mary (Ave Maria in Latin).
The modern Amen Corner is a stub of road that leads to Amen Court, home to a short terrace of 17th-century houses where the canons of the cathedral once lived and where the first meeting of the Campaign for Nuclear Disarmament was held in 1958 at the home of founder John Collins. Present at the occasion also were the politicians Michael Foot and Denis Healey.
There is another Amen Corner, in Tooting, south London, where the A217 road (Mitcham Road) meets Rectory Lane and Southcroft Road.