Smeaton's Tower stood were becoming eroded. Each time a large wave hit, the lighthouse shook from side to side. Smeaton's Tower ceased operation in 1879 with the illumination of Douglass's Tower on an adjacent rock. In 1882 the upper part of Smeaton's Tower was dismantled and rebuilt as a memorial to Smeaton on a new base on Plymouth Hoe, replacing the triangular obelisk that had been built there by Trinity House as a navigation aid in the early 19th century. It was opened to the public by the Mayor of Plymouth on 24 September 1884. The foundation and stub of the old
Lighthouse first lighthouse built there was an octagonal wooden structure, anchored by 12 iron stanchions secured in the rock, and was built by Henry Winstanley from 1696 to 1698. His lighthouse was the first tower in the world to have been fully exposed to the open sea. The civil engineer, John Smeaton, rebuilt the lighthouse from 1756–59; his tower marked a major step forward in the design of lighthouses and remained in use until 1877. He modelled the shape of his lighthouse on that of an oak tree, using granite blocks. He rediscovered and used "hydraulic lime," a form of concrete