York Minster
During the 20th century, the fabric of the Minster endured two major concentrated programs of work in the building’s perpetual history of preservation and restoration: the 1965-6 survey and the 1984 fire.The detailed architectural survey of the Minster in 1965-6 by Bernard Feilden, Surveyor to the Fabric, revealed a need for urgent major restoration, particularly of the foundation of the central tower.
This alarming discovery implemented a major period of restoration work, involving close co-operation between engineers and archaeologists. Strengthening and reinforcement of the central tower's foundations took place between 1967 and 1972 at a cost of £2 million.It was during the excavations that remains of the north corner of the Roman Principia were found.