Despite Château Gaillard's reputation as a great fortress, Liddiard highlights the absence of a well in the keep as a peculiar weakness, and the castle was built on soft chalk, which would have allowed the walls to be undermined. But other sources evoke the presence of three wells in the three different baileys and the soft chalk does not really weaken the very thick walls. Its weakness is more the result of its location (higher hill behind), its extension (more than ) on a long narrow ridge and the difficulties in linking up the different baileys to allow a good communication and to secure an efficient defence without a large garrison.