Mérida Roman Aqueduct (Los Milagros)

Part of the vast Roman infrastructure of Emerita Augusta, the Acueducto de los Milagros carried water from the Proserpina reservoir into the colony from around the 1st century BC. Its surviving stretch soars in triple tiers of granite and brick, alternating grey stone and red brick in a striped pattern up to 25 metres high. Medieval locals, awed that such a structure could still stand after a thousand years, nicknamed it 'the Miraculous Aqueduct'—los Milagros. Much of it has crumbled, leaving a dramatic row of towering, isolated pillars marching across a green valley, their tops now crowned with the huge nests of white storks, an accidental monument to Roman engineering endurance.