Look west from Sarayburnu towards the slopes of Zeyrek above the Golden Horn and the domes line up: Hagia Sophia first, then the Blue Mosque, and Süleymaniye further back. Most of that skyline sits inside a single UNESCO entry. Walking between its buildings, you pass from a Roman hippodrome to an Ottoman mosque complex, from a Byzantine monastery to a timber house, through some sixteen centuries of one city.
How many World Heritage Sites does Istanbul have?
The short answer is one: the Historic Areas of Istanbul, inscribed in 1985 as entry 356. The entry is not a single building but four separate zones of the Historic Peninsula. Hagia Sophia, Topkapı Palace, Süleymaniye and the Theodosian Walls are not separate sites. They are all parts of this one entry.
A minor boundary change in 2017 enlarged the property, which now covers 765.5 hectares.
Why was it inscribed?
Istanbul grew on a peninsula where the Balkans meet Anatolia and the Black Sea meets the Mediterranean. It was the capital of the Eastern Roman Empire and then of the Ottoman Empire, and for more than two thousand years it sat at the centre of political, religious and artistic events.
Four of UNESCO's ten criteria were applied:
- Criterion (i), a masterpiece of human creative genius: Hagia Sophia and the Süleymaniye complex.
- Criterion (ii), influence on architecture elsewhere: Hagia Sophia and the Land Walls.
- Criterion (iii), testimony to a civilisation: the Byzantine and Ottoman civilisations.
- Criterion (iv), an outstanding example of a building type: Topkapı Palace and the Süleymaniye complex.
The four zones and their monuments
1. Sultanahmet Archaeological Park
The zone at the tip of the peninsula is the busiest part of the property. Its main monuments are these:
- Hippodrome of Constantine (324): the chariot-racing ground, now Sultanahmet Square.
- Hagia Sophia (532–537): built for Justinian and turned into a mosque in 1453. It was a museum from 1934 to 2020 and is a mosque again today.
- Hagia Irene: a church from the same reign as Hagia Sophia.
- Topkapı Palace: the residence of Ottoman sultans, extended until the 19th century.
- Sultan Ahmed Mosque: built in the early 17th century.
- Little Hagia Sophia: originally the Church of Saints Sergius and Bacchus.
In 2017 the boundary was extended to take in the Marmara sea walls, the historic grounds of Topkapı Palace and the remains of the Boukoleon Palace. The zone covers 54 hectares and contains 920 listed buildings. A listed building is one registered by the conservation authorities, which cannot be altered without permission.
2. Süleymaniye
At its heart stands the Süleymaniye complex, designed by Sinan between 1550 and 1557. A külliye, or mosque complex, is a group of buildings around a mosque that served the needs of a whole neighbourhood. At Süleymaniye it includes these:
- madrasas, including a medical school,
- a hospital,
- a library and a bath,
- a caravanserai,
- the tombs of Süleyman the Magnificent and his family.
Sinan's earlier Şehzade Mosque and the Aqueduct of Valens, dated 378, are in the same zone. The timber houses around them are a value in their own right: 525 were registered in 1985. The zone now covers 140 hectares and contains 992 listed buildings.
3. Zeyrek
This small zone above the Golden Horn centres on Zeyrek Mosque. The building began as the church of the Pantokrator Monastery, founded by Empress Irene in the 12th century, during the reign of John II Komnenos. The narrow streets and timber houses around it are among the best-preserved examples of a late Ottoman neighbourhood. The area was placed under protection in 1979.
4. The Land Walls
The Theodosian Walls, which close the peninsula on the landward side, were begun in 413 under Theodosius II. A second line added in 447 made them a double wall. On land they run for 6,650 metres. The zone covers both sides of the walls and the remains of the Blachernae Palace.
Nearby, the Chora Church, now Kariye Mosque, is the zone's best-known building, with mosaics and paintings from the 14th and 15th centuries. The Marble Tower was added to the zone in 2017. The zone covers 562 hectares and contains 701 listed buildings.
The four zones at a glance
| Zone | Main monuments | Area |
|---|---|---|
| Sultanahmet Archaeological Park | Hippodrome, Hagia Sophia, Hagia Irene, Topkapı Palace, Sultan Ahmed Mosque | 54 ha |
| Süleymaniye | Süleymaniye complex, Şehzade Mosque, Aqueduct of Valens | 140 ha |
| Zeyrek | Zeyrek Mosque (Pantokrator), timber houses | — |
| Land Walls | Theodosian Walls, Blachernae, Chora | 562 ha |
Nearby, but outside the listing
Not every old building in Istanbul falls inside the UNESCO boundary. The Galata Mevlevi Lodge, across the Golden Horn in Beyoğlu, lies outside the four zones. On the peninsula, the Pammakaristos (Fethiye) is a Byzantine building worth seeing for its mosaics.
Istanbul sites on the Tentative List
Before a place can become World Heritage it must appear on the country's Tentative List, the inventory of possible future nominations. Being on it means a full nomination may follow; it does not make the place World Heritage. Three Istanbul entries are on Türkiye's list:
- Yıldız Palace Complex (2015, Beşiktaş): pavilions and gardens on a hill above the Bosphorus. Abdülhamid II lived here for 33 years, from 1876 to 1909, and made it the seat of government. The Malta, Çadır and Çit pavilions were built under Abdülaziz by architects of the Balyan family.
- Nuruosmaniye Complex (2016, Fatih): just east of the Grand Bazaar, with a mosque, madrasa, soup kitchen, tomb, library and water fountain. Work began in 1749 under Mahmud I and ended in 1755 under Osman III.
- Galata Tower and Yoros Fortress (2026, Beyoğlu and Beykoz): both belong to a joint entry of ten Genoese sites in Türkiye. It traces the Genoese trading network that ran from the Aegean to the Black Sea between the 13th and 15th centuries; Amasra, Sinop and Çeşme fortresses are among the other components.
Planning a visit
The zones are far apart, so seeing all four in one day is hard. Sultanahmet fills a day on foot. Süleymaniye and Zeyrek are close together and fit into half a day. The walls run a long way, from Yedikule to Ayvansaray, so walking one stretch or focusing on the area around the Chora is more realistic. Each building sets its own visiting rules, so check official notices before you go. Visits to mosques may be restricted at prayer times.
Frequently asked questions
When was Istanbul added to the World Heritage List?
In 1985, when the Historic Areas of Istanbul were inscribed under four criteria.
Is Hagia Sophia a separate World Heritage Site?
No. It lies in the Sultanahmet zone of the Historic Areas of Istanbul and is one of the entry's key monuments.
Is Topkapı Palace on the UNESCO list?
Yes. It stands in the Sultanahmet Archaeological Park zone and is named in the reasons for inscription.
Are Galata Tower or the Bosphorus mansions included?
They are not part of the World Heritage property, which covers only the four zones of the Historic Peninsula. Galata Tower, however, joined the Tentative List in 2026 as part of a group of Genoese sites.
How large is the property?
After the 2017 boundary change it covers 765.5 hectares.