Often a medieval bridge is extremely long and included a long stone causeway which leads up to it across a flood plain. This is pierced by subsidiary arches which do not regularly have channels of water flowing through them. They are used, however, at times of flood to allow the swollen waters to escape away, instead of ponding up behind the bridge. Folly Bridge, Oxford, had a causeway with no less than 42 arches in the 16th century. Heyford still has eight and Abingdon, Ock Bridge has seven.
Further structures connected with bridges include chapels built for bridge hermits.
Gateways and drawbridges were also found. Folly Bridge had both. In 1646 four of the arches of Wallingford bridge were replaced with wooden drawbridges to help with the defence of the town. They owed their existence to acts of religious charity, orders from government, the calls of commerce, the opportunities of levying tolls, and the thoughtfulness or necessities of great persons. In many parts of the country monasteries or great churches were responsible for building bridges.