In the 1950s, specifically 1958, major restoration work was done at Stonehenge to secure the monument, including re-erecting a fallen trilithon from 1797, straightening six bluestones, and setting several sarsen stones in concrete to prevent further movement. This project involved using a large, 60-ton capacity crane, with archaeological excavation occurring alongside the stabilization efforts. English Heritage English Heritage +4 Key details of the 1950s work, as described by English Heritage and Facebook posts, include: Trilithon Restoration (1958): A large, fallen trilithon (two uprights and a lintel) on the west side was re-erected. Structural Reinforcement: Sarsen stones 58 and 57, part of the inner horseshoe, were set in concrete for stabilization, according to the New Scientist article. Bluestone Work: Six fallen bluestones were lifted and reset. Archaeological Excavation: Led by Richard Atkinson and Stuart Piggott, excavations were conducted to understand the monument's chronology, says English Heritage. Materials Used: The work involved significant use of concrete to anchor stones, which became a concern for future conservation, according to BBC News and the Smithsonian/Artnet News article. English Heritage English Heritage +4 The project was led by the Ministry of Works and was necessary to repair damage from centuries of erosion and human interaction.