In the Spanish town Calzada del Bejár, in the province of Extremadura just south of Zamora, the wooden porches of the houses are held up with Roman milestones. The Via de la Plata, one of the caminos to Santiago de Compostela, was a major Roman trade and droving route. It ran south to north, from Sevilla to Astorga. The droving route is still there in sections — legislated to be 75m wide, with low stone walls on either side, called a cañada. Millions of domestic animals were herded up and down its reaches by season, on their way to market. Some sections of the famous Roman roads are there as well, on which a well-equipped army could move remarkably quickly. (60km per day for carts, If I remember the interpretive sign correctly.) Every mile was marked by stone pillar, quarried hundreds of miles away, carved with the mile notation and maybe praise for the emperor. In modern times Spaniards are hauling these markers out of whatever places they’ve fallen into, and erecting them once more on the pathways and roads where they were originally.