Interior of the Blue Mosque built by Sultan Ahmet I in 1609, designed by architect Mehmet Aga, Istanbul, Turkey, Europe

Byzantine architecture of Aya Sofya (Hagia Sophia), constructed as a church in the 6th century by Emperor Justinian, a mosque for years, now a museum, UNESCO World Heritage Site, Istanbul, Turkey, Europe

Byzantine architecture of Aya Sofya (Hagia Sophia), constructed as a church in the 6th century by Emperor Justinian, a mosque for years, now a museum, UNESCO World Heritage Site, Istanbul, Turkey, Europe

Byzantine architecture of Aya Sofya (Hagia Sophia), constructed as a church in the 6th century by Emperor Justinian, a mosque for years, now a museum, UNESCO World Heritage Site, Istanbul, Turkey, Europe

Byzantine architecture of Aya Sofya (Hagia Sophia), constructed as a church in the 6th century by Emperor Justinian, a mosque for years, now a museum, UNESCO World Heritage Site, Istanbul, Turkey, Europe

Byzantine architecture of Aya Sofya (Hagia Sophia), constructed as a church in the 6th century by Emperor Justinian, a mosque for years, now a museum, UNESCO World Heritage Site, Istanbul, Turkey, Europe

Cathedral de Santa Maria, Murcia, Region of Murcia, Spain, Europe

Gold mosaics on the dome vaults of St. Mark's Basilica in Venice, UNESCO World Heritage Site, Veneto, Italy, Europe

Byzantine architecture of Aya Sofya (Hagia Sophia), constructed as a church in the 6th century by Emperor Justinian, a mosque for years, now a museum, UNESCO World Heritage Site, Istanbul, Turkey, Europe

Cloisters in the Dome Cathedral, Riga, Latvia, Europe

Vittorio Emanuele II Gallery, Milan, Lombardy, Italy, Europe

Vittorio Emanuele II Gallery, Milan, Lombardy, Italy, Europe

Gold mosaics on the dome vaults of St. Mark's Basilica in Venice, UNESCO World Heritage Site, Veneto, Italy, Europe

Basilica of the Holy Sepulchre, Barletta, Barletta-Andria-Trani, Apulia, Italy

Kalon Mosque courtyard, also known as Kalyan Mosque, Kalon Minaret and Mir-i Arab Madrasah behind, Bukhara, Uzbekistan

Chor Minor Madrasah, also known as Chor Minar Madrasah, Bukhara, Uzbekistan

Entrance to Shah-i-Zinda, also known as Shah I Zinda and Shah-i Zinda, Samarkand, Uzbekistan

Gur Emir Mausoleum, also known as Gur Amir, Guri Amir, Gur-E Amir, and Gur-I Amir, Samarkand, Uzbekistan

Kalon Mosque courtyard, also known as Kalyan Mosque, Kalon Minaret and Mir I Arab Madrasah behind, Bukhara, Uzbekistan

Part of Hazrati Imom Mosque, Hazrati Imom Complex, Hazrati Imom Square, Tashkent, Uzbekistan

Hazrati Imom Mosque, Hazrati Imom Complex, Hazrati Imom Square, Tashkent, Uzbekistan

Entrance to Shah-i-Zinda, also known as Shah I Zinda and Shah-i Zinda, Samarkand, Uzbekistan

Gur Emir Mausoleum, also known as Gur Amir, Guri Amir, Gur-E Amir, and Gur-I Amir, Samarkand, Uzbekistan

Famous historic caravanserai, Han, Khan Assad Pacha, Damascus, Syria

Vaulted ceilings, Basilica do Estrela Church, consecrated in 1790, tomb of Queen Mary I, Lisbon, Lisboa, Portugal, Europe

Glass ornamentation, glass vaulted roof, large central dome, QVB, Queen Victoria Building, shopping centre, Sydney, New South Wales, Australia