Sharing a similar fate with the Hagia Sophia of being converted from a church into a mosque, the Kariye Müzesi (also known as Church of St. Savior in Chora) was originally built as a Byzantine church in the 6th century. It was later converted into a mosque by the Ottomans after the Conquest of Istanbul (and then to a museum in the 20th century). Regarded as one of the finest examples of Byzantine architecture, the Kariye Müzesi is home to a myriad of stunning mosaics and frescoes which far outnumber those in Hagia Sophia. Restored to almost its original splendor, look out for a few notable ones such as the ‘Mosaic of the Koimesis in the Naos' and the Anastasis fresco in the Parecclesion. While it may not be as large as other Byzantine churches in Istanbul, the Kariye Müzesi makes up for its small size with an amazing collection of well-preserved frescoes that are said to be some of the most beautiful.