The "Church of Holy Wisdom", Haghia Sophia is among the world's greatest architectural achievements, and more than 1,400 years old, it stands as testament to the sophistication of the 6th century Byzantine capital...built as a church by Emperor Justinian in 537, the Ottomans converted it into a mosque in the 15th century. Designed as an earthly mirror of the heavens, the interior succeeds in imparting a truly celestial feel..highlights are a number of mosaics, remains of Byzantine decoration that date from the 9th century and some of the patterned mosaic ceilings are part of the original 6th century decoration...