Stop 1 — Sultanahmet Square, between the two giants
Begin in the long garden that runs between Hagia Sophia and the Blue Mosque, with a domed grey building at each end of the lawn and a fountain playing in the middle. Stand where you can see both. This narrow strip of park is the heart of old Istanbul — the district called Sultanahmet — and almost everything worth seeing here sits within a few minutes’ walk of the bench you could be standing beside. Give yourself a moment to get your bearings before you look at anything closely.
You are standing on ground that has been the stage of two empires. For a thousand years this was the centre of Constantinople, capital of the Christian Byzantine world; after 1453 it became the imperial core of the Muslim Ottoman one. The two great buildings facing each other across this garden — one begun as a cathedral, one built as a mosque — tell that whole story between them, and this walk simply reads it stop by stop.
Stop 2 — Facing Hagia Sophia
Turn toward the older, earth-red building at the northern end of the square. This is Hagia Sophia, and the shape you are looking at is deceptively humble for what it contains: a broad, low dome riding on a cushion of half-domes, buttressed by heavy walls that have been patched and propped for a millennium and a half. It was completed in the year 537 for the emperor Justinian, who is said to have walked in, thought of the temple of Solomon, and declared that he had outdone it.
For roughly nine hundred years this was the greatest church in Christendom, the seat of the Orthodox patriarch and the place where Byzantine emperors were crowned. Then, in 1453, the Ottoman conqueror Mehmed II rode into the city and had it converted to a mosque. It served as one for nearly five centuries, became a museum in 1935, and was returned to use as a mosque in 2020 — so the building in front of you has been, in turn, cathedral, mosque, museum and mosque again.
Stop 3 — Reading the domes and minarets
Look at the four minarets that stand at the corners. They do not match, and that is the clue to the building’s double life: none of them is original, because the church had no minarets at all. The Ottomans added them one at a time after 1453, in different reigns and slightly different styles, to mark the building as a mosque — the plainer brick one and the three paler stone ones were raised across more than a century.
Now let your eye settle on the central dome. When it was built it was the largest in the world, a little over thirty metres across, and it seemed to float because a ring of forty windows around its base floods the interior with light and hides the masonry that carries it. It has cracked and half-collapsed in earthquakes and been rebuilt more than once, which is why the profile looks slightly flattened. Even from outside, try to imagine that lit rim of glass hanging above the hall — the effect that made medieval visitors describe heaven.
Stop 4 — Crossing to the Blue Mosque
Walk the length of the garden to the domed building at the southern end. This is the Sultan Ahmed Mosque, known the world over as the Blue Mosque, and it was built deliberately to answer Hagia Sophia across the square. The young sultan Ahmed I commissioned it, and it was finished in 1616 after seven years of work by the architect Sedefkâr Mehmed Ağa, a pupil of the great Ottoman master Sinan.
Notice how the building climbs. Small domes over the courtyard step up to larger ones, and those in turn lead the eye to the single great dome at the centre, so the whole mass seems to swell upward from the ground — a cascade the architect arranged so that no matter where you stand, the silhouette rises rather than sits. Unlike Hagia Sophia, this was purpose-built as a mosque, and it remains an active one, so its rhythms are still set by the five daily calls to prayer.
Stop 5 — The courtyard, the minarets and the tiles
Step into the great forecourt, ringed by an arcade of small domes around an open marble floor. From here, count the minarets: there are six, and that number once caused a scandal. The story goes that Sultan Ahmed asked for altın — gold — minarets and his architect heard altı, the word for six, an unheard-of match for the sacred mosque in Mecca, which then also had six. To settle the offence the sultan is said to have paid for a seventh minaret to be added in Mecca.
The mosque earns its nickname inside, where more than twenty thousand handmade ceramic tiles from the kilns of İznik line the upper walls and galleries in blues, greens and whites, so that the whole interior takes on a cool underwater glow when the light is right. It is a place of worship first: it closes to visitors during the five daily prayers, everyone removes their shoes at the door, and shoulders, knees and hair should be covered — wraps are lent free at the entrance.
Stop 6 — The ancient spine of the Hippodrome
Come back out to the open square on the mosque’s western side and look for a line of monuments standing along its length. You are now on the track of the Hippodrome, the vast chariot-racing stadium of Byzantine Constantinople, where perhaps a hundred thousand spectators once roared for rival teams and where riots could topple emperors. The arena itself is gone, buried under the square, but its central barrier survives as this row of stone landmarks.
Three in particular reward a look. The pink granite Obelisk of Theodosius is genuinely Egyptian, carved for a pharaoh around 1450 BC at Karnak and shipped here to be raised in 390 AD, its hieroglyphs still crisp after thirty-four centuries. Near it, a strange sunken bronze spiral is the Serpent Column, brought from the temple of Apollo at Delphi and cast to celebrate a Greek victory over Persia in 479 BC. Beyond stands the rough stone Walled Obelisk, once sheathed in gilded bronze that crusaders stripped away.
Stop 7 — Down into the Basilica Cistern
A short walk back toward Hagia Sophia brings you to a modest low building with a queue and a stairway leading down. This is the entrance to the Basilica Cistern, and nothing about the doorway prepares you for the space below. Descend the stone steps and the noise of the street falls away; you emerge onto raised walkways in a vast, dim, echoing hall of water, the largest of the hundreds of cisterns that lie beneath the old city.
It was built in 532 for the same emperor, Justinian, who raised Hagia Sophia — a covered reservoir the size of a cathedral, which is exactly how it got its name, since a great basilica once stood on the ground above. Its purpose was strategic: it held tens of thousands of tonnes of water piped in from forests miles away, so that the imperial palace nearby could survive a siege or a summer drought. For centuries after the conquest it was half-forgotten, until locals were found lowering buckets — and catching fish — through holes in their floors.
Stop 8 — The forest of columns and the Medusa heads
Follow the walkway between the columns. There are three hundred and thirty-six of them, marble shafts nine metres tall set in a grid of twelve rows, and almost none of them match — they were gathered second-hand from older ruined temples and buildings across the empire, so you will pass fluted columns beside plain ones and capitals of different orders standing side by side. Fish still move in the shallow water below the boards, and the whole hall drips and glimmers under coloured light.
Make your way to the far north-western corner, where two column bases are carved with the face of Medusa, the snake-haired gorgon of Greek myth. One is set on its side and the other completely upside down, and no one knows for certain why. The practical answer is that they were simply useful blocks of the right size, reused with no ceremony; the romantic one is that inverting her gaze was thought to cancel the power to turn onlookers to stone. Standing over them is a fitting place to end — Egyptian pharaohs, Greek gods, Christian emperors and Ottoman sultans, all within a few hundred metres of one another.
