Starting our perambulation at the =East End=, it will be noticed that the so-called Lady Chapel is actually an enlargement of the choir, such as we find on a much grander scale at Durham or Fountains, and may be compared to the "Presbytery" at Chichester, from which the Lady Chapel projects, or to the "New Building" at Peterborough Cathedral. This addition was made to the church by Peter de Rupibus in the thirteenth century, as a retro-choir or ambulatory. It was carefully restored by Mr. George Gwilt, in 1832, from much external mutilation to something like its original state. The eastern side consists of four bays, divided by buttresses, and surmounted by pointed gables, with ornamental crosses on the apices. In each of the gables there is a triplet of narrow lancet windows, which light the space between the internal vault and the roof. They have sculptured heads in the moulding above the central light in each triplet. The bays below are lighted by a similar series of larger windows of simpler construction, the moulding of the sides being carried over the lancet points in unbroken continuity. In the north-east corner there is a short hexagonal stair turret, but the opposite corner is simply supported by ordinary buttresses. The walls are made up of rubble and flints, with ashlar dressing, as is supposed to have been the case throughout the original church, where, however, the flints are said to have been squared. In the reign of Edward III, a small Lady Chapel was built against the east end of this retro-choir: it projected from the second bay from the south, where the window was removed to connect it with the church. After the interment of Bishop Andrewes within it, this little appendage became popularly known as the "Bishop's Chapel." It was demolished in 1830, on the ground of its supposed interference with the approach to the new London Bridge; but as it only projected thirty-four feet (a distance which would have placed it well within the present churchyard railing) its destruction seems to have been an unnecessary act of vandalism. The retro-choir itself narrowly escaped sharing its fate, but was fortunately spared, and the tomb of Bishop Andrewes was removed to its present position immediately behind the high altar. The true Lady Chapel being destroyed, the dedication seems to have been popularly transferred to the structure so closely associated with it, and most people concerned are now very unwilling to part with the familiar name.[15]