Hagia Sophia is surely one of the most widely-recognized buildings on Earth, which is amazing considering that the world is so populated with other buildings modeled on it or even directly copied from it. Built as a Byzantine church, it became the center of Eastern Orthodox Christianity, and then a mosque that became a template for thousands of others, as near as its neighbor, the Blue Mosque, and as far away as the Taj Mahal.
It's also the answer to Where in the World is TravelGumbo #103; one member came up with the correct answer...kudos to Port Moresby, who was able to sort it out from the first clue, before the others were posted.
The first clue; designs made by splitting marble into extremely thin panels and matching two together for symmetry. Justinian imported marble from all over his empire.
There's a lot about Hagia Sophia that's unique. It's one of the world's oldest buildings; it was put up by the Roman Emperor Justinian between 532 and 537 AD. It's also one of the largest until very modern times, and for nearly 1000 years it was the largest until Seville's cathedral surpassed it. It's so huge that the Statue of Liberty could stand under the dome and not reach it. It served as a Christian church until 1453 (with a 70-year stint as a Catholic cathedral in the 13th century) and then as a mosque, for a time the main one of the Ottoman Empire, until 1931, and since 1935 as a museum.
It's quite an architectural marvel, too. Justinian wanted it to impress everyone with his power and magnificence—that was important to him because he had just barely put down a rebellion that raged through the city and destroyed the previous church. To create a huge uninterrupted space (no columns in the middle!) he hired two Greek mathematicians as architects; they created a unique structure to allow the huge dome to sit on a square support over the world's largest indoor space.
A recent Nova describes it in great and interesting detail—as well as describing the search to understand how it has withstood so many earthquakes. You can find that episode on PBS at this LINK.
Note how the crowd (never small!) is dressed for the weather
On our recent trip to Turkey, Hagia Sophia was high on our list of what to see, although in the end we didn't spend as much time there as we'd expected. That's because the day was bitter cold, the first day of the snowstorm, and it quickly became obvious that the building is not heated. And what heat there was, as physics tells us, rises to the top—and the top was far away. Taking photos with gloves on was not easy; taking them off was painful, and the cold floors made standing still difficult. We fled, all too soon, to a warm cafe with pastry and tea. Another time we must return.
But moving on. After passing our time on line, we entered the building through an outer gallery, and were blown away by the scale of the space. In fact, the building, and especially the main space is so huge it is at first hard to concentrate on the details. Even with a substantial portion blocked off for research and renovation, huge is what you see. It takes an effort to see detail.
And the detail is beautiful. Cut-marble slices that form symmetrical panels. Ornate railings and lacy stone and gold screens. Arabic script in panels and stained glass. Lights playing in different colors and directions through glass and space.
For anyone who has seen the incredible Byzantine mosaics at Ravenna or the Capella Palatina in Sicily, there will be some disappointment here. Most of the mosaics that once covered acres of wall space were plastered over when it became a mosque (partly because of religious difference, and partly because Muslim law frowns on depictions of people). And the ones that are visible in many cases give only a hint to their original color and glory.
It's not clear what the future holds for the hidden artworks. The Nova episode describes high-tech efforts to locate them under the plaster—but even if found, they may not be revealed or restored, because in many cases, including the inside of the dome, they are covered in Islamic art, including masterpieces of calligraphy. Nonetheless, the blend of cultures, shapes and colors create a lasting and beautiful impression.