Pammakaristos Church (Turkish: Pammakaristos Manastırı) is a former Greek Orthodox monastery and church in Istanbul, Turkey. It is located in the Fatih district, and is one of the few surviving Byzantine churches in the city. The church was built in the 11th century, and was originally dedicated to the Virgin Mary. The church was converted into a mosque in the 15th century, and was later used as a museum. The church is now open to the public, and is one of the most popular tourist attractions in Istanbul.

1. Location: The Pammakaristos Church is situated in the Fatih district of Istanbul, specifically in the neighborhood of Fener. It is located near other significant historical sites such as the Ecumenical Patriarchate of Constantinople and the Church of St. George.

2. History: The church was originally built in the 11th century during the Byzantine Empire and was dedicated to Theotokos, which means "Mother of God" in Greek. Over the centuries, it underwent several restorations and additions. It served as a center of Byzantine Orthodox Christianity and played a significant role in the religious and cultural life of Constantinople (present-day Istanbul).

3. Architecture: The Pammakaristos Church is an excellent example of Byzantine architecture. It features a cross-in-square plan, a dome, and an apse. The exterior facade is adorned with intricate brickwork and decorative elements. The interior is known for its beautiful frescoes and mosaics, although some have been damaged over time.

4. Museum: Today, the Pammakaristos Church functions as a museum known as the Fethiye Museum. It houses a collection of Byzantine-era artifacts, including religious icons, frescoes, mosaics, and marble carvings. The museum provides visitors with insights into the rich artistic and religious heritage of Byzantine Constantinople.

5. Noteworthy Features: The Pammakaristos Church is renowned for its impressive Byzantine mosaics and frescoes that depict scenes from religious narratives and portray saints, angels, and other figures. The mosaics and frescoes showcase the artistic and cultural brilliance of the Byzantine Empire.

6. Visiting Information: The Pammakaristos Church, now the Fethiye Museum, is open to the public for visitation. However, it's recommended to check the official website or contact the museum directly for the most up-to-date information regarding opening hours, admission fees, and any specific guidelines for visitors.

The Pammakaristos Church, with its historical and artistic significance, offers visitors a glimpse into the Byzantine heritage of Istanbul. It is a notable attraction for those interested in Byzantine art, architecture, and religious history.