Church of Saint Simeon Stylites

The Church of Saint Simeon Stylites is one of the oldest surviving church complexes, founded in the 5th century. It is located approximately 30 kilometres (19 mi) northwestern of Aleppo, Syria. It was constructed on the site of the pillar of Saint Simeon Stylites, a renowned stylite monk. The church is popularly known as either Qalaat Semaan or Deir Semaan. Completed in 490, it was not surpassed as a Christian church until the construction of Hagia Sophia was finished in 537.