The West Gate and its Church
Oxford’s West Gate stood near the junction of the present-day Castle and Paradise Streets, although the exact position is uncertain. The bus in the above photograph would be entering the old medieval town.
The gate fell down or was demolished in the mid seventeenth century.
The medieval Church of St Peter-le-Bailey stood inside the wall to the north-east, in front of the present-day Bonn Square. It was also known as St Peter-in-the-West or as St Peter-at-the-Castle (a bailey being an external wall of a castle).
The OS map of 1876 (below) shows the site of the original St Peter-le-Bailey Church.
The map below of 1850 shows the actual church, and its relationship to the Baptist Church behind:
The original medieval church fell down in 1726, and its replacement on the same site was demolished in 1874 as part of a road-widening scheme. In 2008 its old graveyard was paved over to create the new Bonn Square.
Victoria County History: History of the County of Oxford, Vol. IV
St Peter-le-Bailey Church
From the West Gate, the wall continued a short distance north-west to meet the outer wall of the Castle, where the tour started.
Victoria County History: History of the County of Oxford, Vol. IV, pp. 300–304:
[Oxford’s] City Walls, Gates, and Posterns