Ancient Greek war mask, with form fitting face behind. War has led to a good percentage of human evolution - both in body and technology. Death is the ultimate motivator. For Gondolin! For your dreams!
The 3rd leg of the grand stream, draining Gondolin of stagnant waters and all possibility of flooding. Little round rocks collected for weeks, piled in stacks, laid across the established channel. Erosion prevention is the aim. Beauty a secondary concern.