At Constantinople, Justinian constructed the largest domed basilica: on the site of the 4th century basilica Church of Holy Wisdom, the emperor ordered construction of the huge domed basilica that survives to the present: the Hagia Sophia. This basilica, which "continues to stand as one of the most visually imposing and architecturally daring churches in the Mediterranean", was the cathedral of Constantinople and the patriarchal church of the Patriarch of Constantinople. Hagia Sophia, originally founded by Constantine, was at the social and political heart of Constantinople, near to the Great Palace, the Baths of Zeuxippus, and the Hippodrome of Constantinople, while the headquarters of the Ecumenical Patriarchate was within the basilica's immediate vicinity.