Marqués del Atrio traces its roots to 1899, when Olegario Rivero founded a small underground winery in Arnedo, La Rioja, working out of traditional calados carved into clay-limestone rock. In 2003 the company built its modern headquarters in Mendavia, within Rioja Oriental, creating a facility designed for high-quality, DOCa-certified wines. Today the fourth and fifth generations run a fully professionalized operation producing about twenty million bottles annually across multiple DOs. Production relies on state-of-the-art equipment, rigorous laboratory controls, and an ageing cellar holding more than 10,000 French and American oak barrels.