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The lighthouses, commissioned by Trinity House in 1862 and completed in 1863, served to guide ships towards Harwich harbour (some 1.5km to the north) their different heights enabling the two lights to be aligned on approach. They replaced two late 18th century lighthouses at Harwich (the 'Low' TM2632 : Harwich: The Low Lighthouse and 'High' TM2632 : Harwich: The High Lighthouse lighthouses) which had become unreliable due to shifting sand bars around the mouth of the Stour estuary. A comprehensive pattern of marker buoys in the harbour approach rendered the new lights obsolete in 1917. The lights escaped demolition, but gradually deteriorated through lack of routine maintenance. A major programme of restoration took place between 1983 and 1988.

The two lighthouses are connected by a causeway that is exposed at low tide, and the lighthouses and causeway together form a Scheduled Monument, but not a nationally Listed Building.

The reasons for the scheduling include what is thought to be their unique prefabricated structure, and the early use of screw pile foundations, by which helix or screw bladed iron sections were driven deep into the soft ground in order to provide solid footings for the attached legs. The success of this operation is evident in the lack of any appreciable subsidence since.