After the tower, the earliest surviving parts of the church are the chancel, the eastern part of the south aisle (nearest the altar), and the south door, all dating from the 13th century. The east window of the chancel contains four panels of high quality stained glass, also dating from this period; it is some of the earliest stained glass in Oxford. Next, in the 14th century, came the lady chapel and the north transept (where the organ now is), while the north aisle and the nave date from the 15th century.
The font also dates from this time; it was removed from the former St Martin’s church at Carfax and may have been seen by William Shakespeare, who stood at a baptism in St Martin’s as godfather to the son of an Oxford friend. The pulpit, which came from Lincoln College, is also of note; John Wesley preached from it at the College in 1726.
Visitors to the tower go through the first-floor treasury containing a magnificent display of rare silver - the earliest piece dates from 1562 - and the Charter of 1612, bearing the arms of James I. As you climb the tower you will pass the 19th century clock mechanism and the door of the prison cell, situated nearby, through which the Protestant martyrs, including Archbishop Cranmer, stepped to their deaths in 1556.
The roof of the tower, open to the public, gives a panoramic view of the city and the hills beyond. The entrance to the tower is through the Visitor Reception Centre, where you can buy guide books and other souvenirs.