The nave has a stoup just inside the door on the north wall. The two large windows are fifteenth century but the walls are probably older than this. The thatched roof was replaced in about 1800. The pulpit was dedicated in 1937.
The Royal Arms above the vestry screen to be found at the west end of the Church are those of Queen Anne 1714.
The Church has two wall paintings, unfortunately both very faded. The painting on the North side of the chancel, shown in the picture to the left depicts St John the evangelist holding the poisoned chalice with the poison in the form of a dragon emerging.
The other painting which is on the south wall, shown below, depicts St Christopher carrying the infant Christ across the river. This is probably fifteenth century; it was thought that anyone who looked on this painting would be free from sudden death that day.
In the floor of the nave, a stone matrix indicates the outline of a former brass.
The fifteenth century font is the most cherished possession of the church. It follows a type that is very common in East Anglia. The bowl has eight sides, on four of which are emblems of the Four Evangelists holding scrolls. The emblems are:
an angel for St Mathew
a lion for St Mark
an ox for St Luke
an eagle for St John
The other four panels are occupied by angels holding shields which respectively show the arms of St Edward the Confessor, the arms of the Diocese, instruments of the passion and the usual design of the Holy Trinity.
Around the stem are lions, and the whole is raised on two steps, as so often in East Anglia, thereby giving added dignity to the font. On the upper step is the following inscription "Oratr pro fratribus ac soribus ac benefactoribus gildae Sancti Johannis Baptiste de Castre".
The font cover was donated in 1970 in memory of the Rector, Canon T Blackhouse and was designed by Sir Bernard Feilden.