Madeira Drive owes its existence to land reclamation. At the beginning of the eighteenth century Brighton's fishing industry was in decline in part because of the erosion of its beaches. It was then that the first groynes were built in wood. Wooden piles were sunk into the shore and then planked with wood, the structures set at right angles to the beach. The prevailing south westerly winds drive the shingle along the south coast eastwards, a process known as longshore drift. The shingle is trapped by the groynes and builds up in banks which help to absorb the pounding of the waves and protect the beach and low cliffs, on which Brighton is built, from erosion. With the growth of the shingle bank, the landward end of the beach becomes dry land, and can be build upon. Hence Madeira Drive.
In the nineteenth century wooden groynes were replaced by fewer but larger concrete ones. Eastbourne, by comparison has retained it wooden groynes, which must be installed at very regular intervals along its coast.
There are several groynes on the beach between Brighton Pier in the west of Madeira Drive and Blackrock in the east. About mid-point is the Banjo Groyne, so called because of its shape - the groyne has circular viewing platform. Officially it is the Paston Place Groyne. It was built in 1877, is around 270 feet long and 14 feet wide.
Because of the way the groyne interacts with the eastwards drifting shingle, the wall on its west side is often almost overtopped with the growing mound of shingle, while on its east side there is liitle shingle and a high drop to the beach below. This also means that when the tide is in, there is deep water on the groyne's east side.