These huge stones are now in place around the west front of York Minster.
As we reported last week the security barrier is being installed to protect the cathedral from terrorist attack.
The 12 blocks curve round the front of the Minster leading towards Dean’s Park.
The decision to strengthen security at the front of the Minster was taken by the Chapter of York, the cathedral’s governing body, following recommendations from the Counter Terrorism Unit.
They are already in use at a number of high profile locations around the country including the Tower of London.
New flag stones will be cut and set around the edges of each block. In a statement last week, York Minster said: “The security barrier is a temporary measure: the blocks can and will be removed if the security situation improves in the future.”
Meanwhile concrete blocks were also being installed close to the Assembly Rooms on Blake Street.