When the Hagia Sophia obsoletes, you get its effect anyway. As a result, whether or not you want to build this wonder depends on your technological path. If you're aiming to get Steam Power sooner, pass on this wonder. If you're aiming to get Steam Power later, the Hagia Sophia may be highly useful.
If you lack food, the Hagia Sophia is useful for making up for the lack of Workers you may have as a result.
The Hagia Sophia, or "Church of the Holy Wisdom," was constructed in 530 AD as a Greek Orthodox church. Standing in Istanbul (originally Constantinople), Turkey, it is a beautiful and ornate structure, built of stone and marble, and topped by a golden dome measuring over 100 feet in diameter. An extremely difficult engineering challenge for the time, the dome has collapsed several times during its existence. Four graceful towers stand at the corners of the building.
The interior of the Hagia Sophia is a marvelous space of columns and arches extending up to the dome, which appears almost to float atop the building. The interior was sheathed in colored marble and golden mosaics depicting biblical scenes and images of Christian saints.
In 1453 Constantinople was captured by the Ottoman Turks, and the Hagia Sophia was converted into a mosque. Human images are not welcome in mosques, and many of the mosaics were covered with plaster.
In 1934, Turkish President Kemal Atatürk turned the building into a museum. In recent years some restoration work has been done on the Hagia Sophia, and a few of the mosaics have been uncovered. Despite the ravages of time, the Hagia Sophia remains universally acknowledged as one of the most beautiful buildings in the world.