Does anyone have any ideas on this problem please. Garden surrounded by a stone wall at present. Varying width (3 feet - 1 foot) and height (2 feet - 3 feet). Most is dry stone wall construct with some mortared areas (presumably from repair), sloping face 20-30 degrees. Need to increase height to 5-6 feet to retain a lively dog and provide screening from newly built houses next door. Wall is actually a nice feature and would like to retain. Also it would not be easy to remove (shared boundary). I was hoping to erect some form of fencing on top of the wall to increase the height. I cannot see any way to put metal pins into the wall or erect posts in front or against the sloping wall to support a 3 foot fence above the wall. Any advice very welcome