Officially known as Plaza de Cánovas del Castillo, the next roundabout south of Cibeles is something of a crossroads of Spanish nobility. The Ritz and the Palace, two of Madrid’s most exclusive hotels, glower at each other across the plaza with self-righteous grandeur, while the Museo Thyssen-Bornemisza and the Prado do likewise in competition for the title of Madrid’s best-loved repository of fine art. The centrepiece is an ornate fountain and 18th-century sculpture of Neptune, the sea god, by Juan Pascual de Mena.