“The historic walls are under threat as never before from a combination of an exploding population that has put pressure on land and housing, as well as local politics. … Houses and commercial buildings have sprung up on [some] demolished sections or been turned into dumping grounds for rubbish, litter and sewage from the ever more crowded city. Elsewhere, excavators dig into the fortifications for the red iron- and aluminium-rich rock laterite, which is loaded onto donkeys and taken away for use in construction and renovation.”