The monuments themselves were listed and purchased by the State at the start of the 20th century to protect them against quarrymen, and while this was successful at the time, in the middle of the century, redevelopment, changes to agricultural practices and increasing tourism bringing visitors to the stones led to rapid deterioration. The "Ministère de la Culture et de la Communication" (Heritage Ministry) re-examined the issue starting in 1984, and subsequently set up the ‘Mission Carnac’ in 1991 with the aim of rehabilitating and developing the alignments. This involved restricting public access, launching a series of scientific and technical studies, and producing a plan for conservation and development in the area.