Keep in mind the closures for these top sites in Istanbul 2020
Archaeological Museums (Arkeoloji Müzeleri) Closed: Monday, and until 13.00 on the first day of religious holidays
Basilica Cistern (Yerebatan Sarnıcı) Museum is open seven days a week. Exceptionally, the first day of religious holidays is opened at 13.00.
Big Palace Mosaic Museum (Büyük Saray Çinileri Müzesi) Closed: Monday, and until 13.00 on the first day of religious holidays
Blue Mosque (Sultanahmet Camii) Closed: 30 min before untill 30 min after praying times it is closed for visitors, on Fridays it is available after 14:00 for visitors.
Dolmabahçe Palace (Dolmabahçe Sarayı) Closed: Thursday, January 1st and the first days of religious holidays
Egyptian or Spice Bazaar (Mısır Çarşısı) Closed: No closing days
Fortress of Europe (Rumeli Hisarı) Closed: Wednesday, and until 13.00 on the first day of religious holidays
Galata Tower (Galata Kulesi) Closed: No closing days
Grand Bazaar (Kapalı Çarşı) Closed: Sundays
Hagia Sophia (Ayasofya Müzesi) Closed: Mondays. Special Days: Hagia Sophia Museum is not available for visiting in the first days of Ramadan and Sacrifice Festivals for half time.
Harem Closed: Tuesday, and until 12.00 on the first day of religious holidays
Kariye Museum (Kariye Müzesi) Closed: Wednesday, and until 13.00 on the first day of religious holidays
Süleymaniye Mosque (Süleymaniye Camii) Closed: During prayer time
Topkapi Palace (Topkapı Sarayı) Closed: Tuesday, and until 12.00 on the first day of religious holidays
Turkish & Islamic Art Museum (Türk İslam Eserleri Müzesi) Closed: Monday, and until 13.00 on the first day of religious holidays
Yıldız Palace (Yıldız Sarayı) Closed: Tuesday, and until 13.00 on the first day of religious holidays