Holding up these and many other walls are gabion baskets. They look like a bad art school project about industry vs nature, or some such. Here they are decorated with massive bolts. This is a pretty main route for tourism and freight, and the main route to many satellite communities. All the architects and urban designers were on holiday when they were planning this retaining wall, so the engineers just cracked on with it anyway.
Photo © 2009 Alex Gilks.