Hagia Sophia: The Building That Has Been Both the Most Important Church and One of the Most Important Mosques in the World

Hagia Sophia was consecrated as a Byzantine cathedral in 537 CE and held the record for the world’s largest domed structure for nearly a thousand years. The dome’s 31-metre diameter seems to float above the interior because of the ring of windows at its base that diffuses light and visually separates the dome from the walls below. Emperor Justinian I, standing inside after its completion, reportedly said: “Solomon, I have surpassed you.”

In 1453, Mehmet II entered the building after the fall of Constantinople and converted it to a mosque within hours. The great Christian mosaics were plastered over. Large calligraphic roundels were added. In 1934, Ataturk secularised it as a museum, and the mosaics were restored for public view. In July 2020, a Turkish court reconverted it to an active mosque, and entry is now free but with mosque conditions: shoes off, women cover their heads, silence during prayers.

The building is one of the most argued-over structures in the world – historically, politically, architecturally. Standing inside it, you can see the actual layering: Byzantine gold mosaics of Christ and the Virgin still visible beneath the Islamic calligraphy added 900 years later, the massive Ottoman medallions hanging where chandeliers once hung, the Roman columns plundered from Ephesus and Baalbek supporting a building that incorporated all of them.

Visiting in 2026

Entry is free. The building is open daily (closed during Friday prayers for a portion of the morning). The upper gallery is accessible via a ramp and contains some of the finest Byzantine mosaics visible in the building, including the Deesis mosaic of Christ flanked by the Virgin and John the Baptist, considered one of the masterpieces of Byzantine art. Arrive as early as possible; the queue for the upper gallery builds by mid-morning.

Dress respectfully: women cover their heads (scarves available at the entrance), and both men and women cover shoulders and knees. Shoes must be removed or covered.

The Surroundings: Sultanahmet

The Blue Mosque (Sultan Ahmed Camii) stands directly across the courtyard. It was completed in 1616 as a deliberate rival to Hagia Sophia in scale and ambition – the architect Sedefkar Mehmed Agha gave it six minarets when only the mosque in Mecca had six, which required subsequent negotiation and compromise. Entry free, mosque conditions apply.

Topkapi Palace, a five-minute walk, was the administrative centre of the Ottoman Empire for four centuries. The Harem section requires a separate ticket and is the most interesting part; the Treasury holds the Topkapi Dagger and the Spoonmaker’s Diamond (86 carats, surrounded by 49 smaller diamonds). Allow a full day.

Getting Around Istanbul

The T1 tram runs from Kabatas through Sultanahmet and is the fastest connection to the main sites. The Istanbulkart contactless card covers trams, metro, ferries, and buses. A Bosphorus ferry ride from Eminonu or Karakoy is one of the world’s better cheap experiences: a working commuter boat through the strait separating Europe and Asia, with views of the Ottoman waterfront.

Where to Eat and Stay

For food near Sultanahmet: Balıkçı Sabahattin on the waterfront side of the Old City is the best-regarded traditional fish restaurant in the area. Nusr-et (Salt Bae’s origin restaurant) in Nisantasi is worth knowing about even if you have no intention of going. For eating with locals rather than tourists, Karakoy and Balat are the current neighbourhood restaurant areas.

The Four Seasons Hotel Istanbul at Sultanahmet occupies a converted 19th-century prison directly beside the walls of Hagia Sophia. It is one of the better hotels in the city for the proximity to the monuments; rates reflect accordingly.