Palacio Ducal de Medina Sidonia Monument · Sanlúcar de Barrameda, Costa Noroeste, Cádiz The historic residence of the Dukes of Medina Sidonia in Sanlúcar, home to the Archive of the House of Medina Sidonia, one of the most important private documentary collections in Spain for the study of modern history. Photo: Antonio M. Romero Dorado (CC BY-SA 4.0) What to see and do in Sanlúcar de Barrameda