Located just outside Barcelona, Spain, Castell de Santa Florentina serves as Horn Hill, the ancestral home of Samwell Tarly. It appears in season six when Sam brings Gilly home to meet his family, then later runs away with the Valyrian steel sword, Oathkeeper, to the Citadel. Built on the foundations of an ancient Roman Domus (the type of old Roman house occupied by the upper classes), in the 11th century, it served as “fortification in order to defend from frequent pirates’ attacks. Remains of this building are still a part of St. Florentina’s Castle.