The twelve sacred hills of Imerina are hills of historical significance to the Merina people of Madagascar. Located throughout Imerina, the central area of the highlands of Madagascar, the sites were often ancient capitals, the birthplaces of key public figures, or the tomb sites of esteemed political or spiritual leaders. The first set of sacred sites was designated by early 17th-century king Andrianjaka. The notion was re-sanctified under late 18th-century king Andrianampoinimerina, who replaced several of the earlier sites with new ones. More than 12 sites were thus designated as sacred over time, although the notion of twelve sacred hills was perpetuated because of the significance of the number 12 in Malagasy cosmology. Today, little concrete evidence of the former importance of many of these sites remains, but the significant archeological and cultural heritage of several of the sites has been preserved. The historic significance of the sites is best represented by the Rova of Antananarivo at Analamanga, the ancient fortified city at Alasora, the houses and tombs of the andriana (noble class) at Antsahadinta and the ancient fortifications and palaces at Ambohimanga, protected as a UNESCO World Heritage Site since 2001.