In 1959 Frank Jenkins investigated Tower 6, a Medieval wall tower on the city wall in the Canterbury Bus Station. Excavations were carried out to a depth of 2.44m and eleven courses of stone were exposed. He concluded that the tower had been built following a major rebuild of the city wall on new foundations. The ground level was then raised by a layer of dark loamy soil 46cm thick. The construction trench of the tower was put into this layer and also cut into the scarp of the ditch. The base of the tower abutted the city wall and had a chalk and mortar rubble core. This was faced with flint and with ashlar. Stratified deposits wihin the strcuture produced pottery which indicated c.1390 for the earliest date of construction. The tower has since been rebuilt in c.1430, but destroyed in 1782.

Frere, SS, Stow, S, and Bennett, P, 1982, Excavations on the Roman and Medieval Defences of Canterbury. (Monograph). SKE28530.