muralla
/muˈɾaʝa/ · B2 · noun · f
large wall built to protect cities or territories
🏰🧱 muralla = muro (wall) + -alla, a big wall; Latin murus
Spanish muro means wall, and muralla is the bigger, defensive version around a city. The same Latin root murus gives English mural (painted on a wall) and immure (to wall in).