9 Must-See UNESCO World Heritage Attractions in Istanbul

The Hagia Sophia —perhaps Istanbul’s most famous site—is a stunning piece of living history. Over the course of 1,500 years, this captivating 6th-century structure has transitioned from cathedral to mosque to museum—and is now, again, used as a mosque. The building’s kaleidoscopic beauty expertly melds the art and architecture of the Byzantine and Ottoman empires and includes a plethora of beautiful art, such as the well-preserved Christian mosaics and gilded Quranic verses that adorn the interior. No trip to the city is complete without a visit to this UNESCO treasure.

The Blue Mosque (Sultan Ahmet Camii) ranks high on Istanbul bucket lists and is conveniently located in the heart of the Sultanahmet District, opposite the Hagia Sophia. Commissioned by the youthful Sultan Ahmed I, the 17th-century marvel was completed in only seven years. Adorned with over 20,000 handcrafted tiles from the nearby city of Iznik and featuring intricate calligraphy, chandeliers, and Quranic verses, the mosque is a captivating display of artistry combined with spiritual significance. For a truly immersive experience, take a guided tour of the iconic jewel.

The Topkapi Palace was the primary home of Ottoman sultans for nearly 400 years (1478–1856) and had the capacity to house up to 4,000 people. The building became a museum in 1924, and it now preserves significant Muslim relics, including the Prophet Muhammad's alleged cloak and sword. Other highlights include opulent Ottoman robes, the famed Spoonmaker's Diamond, and the intricately designed harem area, which offers a glimpse into the lavish lives of the Ottoman rulers.

Insider tip: There is an additional fee to visit the harem in the Topkapi Palace, so be sure to purchase the combination ticket upon arrival if you want to see it.

The 16th-century Suleymaniye Mosque, designed by the royal architect Mimar Sinan (under the direction of Sultan Suleiman the Magnificent), is situated near the Spice Bazaar, away from the tourist center—and, therefore, sees fewer tourists than other, comparable, sites. Its relatively simple interior is augmented by intricate stained glass and Quranic verses. Sinan's innovative architectural features include elastic, earthquake-resistant foundations and a ventilation system. The Suleymaniye Mosque is the final resting place of Sultan Suleiman and his influential consort, Roxelana (Hurrem Sultan)—and of its architect, Sinan, himself. Travelers who take a Bosphorus Cruise can enjoy a clear view of the mosque’s exterior.

Insider tip: If visiting Süleymaniye Mosque in the winter, make sure to walk to the nearby Vefa Bozacisi to taste boza, a thick fermented malt drink topped with cinnamon and roasted chickpeas that is beloved by Turks everywhere.

The Istanbul City Walls, constructed in the 5th century under the direction of Emperor Theodosius II, served as a robust defensive system for over a millennium. Measuring approximately 7 miles (12 kilometers) in length, the walls featured intricate fortifications that included towers and moats. These triple-layered defenses were said to be impregnable, and they thwarted numerous sieges—failing only during the Ottoman Empire's successful conquest in 1453. Today, many sections of the walls have been damaged beyond repair, but there are a few designated sections where you can climb a portion of the wall. The most convenient access point is near the Kariye Museum (Kariye Müzesi). For the ultimate sightseeing experience, take a tour of the Fener-Balat neighborhoods that includes a stop at the walls.

Insider tip: Do not climb the walls in dark or inclement weather, and always exercise extreme caution as the steps are steep and there are no safety precautions (like railings). When in doubt, defer to locals and tour guides when it comes to wall safety.

The Hagia Irene (Aya Irini), commissioned by Emperor Constantine I in the 4th-century, was Constantinople’s first church. After the first version of the building was destroyed in the Nika revolt of 532 CE, Emperor Justinian I undertook its reconstruction, resulting in the present-day structure. After the Ottoman conquest of 1453, the church became a part of the grounds of Topkapi Palace and served various purposes, ranging from a janissary armory to a weapons museum. Today the Hagia Irene is known not only for its architecture and history but also for its fantastic acoustics. The church also functions as a performance venue during the city’s world-renowned Istanbul Jazz Festival. Take a deeper dive into the building’s history with a pre-downloaded audio guide or on a guided tour.

Insider tip: The Istanbul Jazz Festival takes place at several venues throughout the city. Be sure to book your tickets well in advance, as they sell out quickly.

The Hippodrome of Istanbul, constructed in the 3rd-century and completed during Constantine I's reign, was a vast racetrack with an estimated seating capacity of 100,000. In addition to chariot races, the site also hosted political discussions—making it one of the city’s rare locations that welcomed royalty, politicians, and commoners alike. It was also the starting point of the Nika revolt in 532 CE, which resulted in 30,000 casualties. The Ottomans, who were disinterested in chariot racing, used parts of the venue for building stone. Eventually, the Hippodrome fell into complete ruin, leaving only three surviving monuments: the Obelisk of Theodosius, Serpent Column (Delphi Tripod), and Obelisk of Theodosius. To get the most out of your visit and learn about the area’s history, you take a guided tour of the city that stops here.

The Zeyrek Conservation Area was established to preserve earthquake-damaged Ottoman mansions and restore their lattice work, decorative wooden screens (mashrabiya), overhanging eaves, and pastel paint to their former, 19th-century, splendor. The area’s top landmark is the 12th-century Zeyrek Mosque (originally the Monastery of the Pantokrator), one of the city’s best-preserved Byzantine structures. Other local sights include the 4th-century Roman Valens Aqueduct, and Fatih Memorial Park. If you visit Zeyrek on a Wednesday, you can also catch the Fatih Carsamba Pazari (Wednesday Market), where locals pick up fresh produce, clothing, and other odds and ends.

Insider tip: The Zeyrek neighborhood is more conservative than most tourist-friendly areas of Istanbul, so though it is not required, you may feel more comfortable if you dress modestly when visiting this area.

Though the Archeological Site of Troy lies outside Istanbul’s city limits, this UNESCO World Heritage Site, near Canakkale, is a popular day trip destination for many travelers. Since its founding in the Early Bronze Age (3,000 BCE), the city was rebuilt multiple times after the Trojan War, notably in the Troy II and Troy VI phases. Points of interest include the symbolic location of the Trojan Horse deception, the possible former site of the Scaean Gates, and areas associated with Achilles' confrontation with Hector—all of which offer tangible connections to the Iliad's legendary narrative. Visitors can also explore the site’s life-size reproduction of the Trojan Horse.

Insider tip: Head to Canakkale’s city center to see the Trojan Horse model used in the 2004 film Troy.