build them high

I was at a meeting today at the Dept for Justice and in the foyer, saw this representation of 3 sets of walls in 3 jurisdictions. The number of years indicates how long the walls were/are in existence which the height represents proportionally (see additional photo). The other figure is the height of the wall.
Our wall in Cupar street, Belfast is the longest in existence and the highest.
I wonder how long will we accept the maxim "high walls make good neighbours" and instead work collectively to create the context in which we can remove them.
While we may get there eventually, we need also to address the walls in our heads and hearts as they are the hidden element, much harder to reach and remove.