Yeraltı Camii: Istanbul’s Underground Ottoman Mosque
Site at a Glance
- Rating
- 4.8
- Popularity
- Medium
- Country
- Turkey
- Primary era
- Medieval
- Eras represented
- Medieval, Early Modern
- Civilizations
- Byzantine, Ottoman
- Site type
- Religious
- Remains
- Mosque
On this page8 sections
History
Yeraltı Camii is an underground Ottoman mosque in Istanbul, Turkey, occupying the former cellar of a Byzantine fortress in Karaköy, within the Beyoğlu district. The fortress, sometimes identified as the Kastellion of Galata and called the Imperial Cellar in Ottoman records, formed part of the defensive landscape of Constantinople, the capital of the Eastern Roman Empire.
The Byzantine Fortress
The date of the fortress’s construction remains uncertain. The Ottoman traveler Evliya Çelebi attributed it to Umar ibn Abd al-Aziz, an Umayyad caliph, in 711. A tradition preserved in the tenth-century Patria of Constantinople instead connects the fortress with the reign of the Byzantine emperor Tiberius II, around 578–582. In that account, it was built as a defense against a Bulgarian ruler who had advanced toward Constantinople.
The fortress consisted of a high tower and a courtyard enclosed by high walls. A chain used to block access to the Golden Horn was attached at the site. These features appear in a fifteenth-century engraving by Cristoforo Buondelmonti, while later drawings by Matrakçı Nasuh from 1573 and illustrations in the Hünername from 1584 do not show either the Galata Fortress or the Imperial Cellar.
Ottoman Uses and Conversion
After the Ottoman conquest of Constantinople in 1453, the cellar served several functions, including ammunition storage and use as a water cistern. Ottoman tradition also held that the belongings of captured Umayyad warriors were kept inside after being sealed with molten lead. This tradition gave rise to the name “Leaded Cellar,” reflected in the mosque’s Turkish name, Yeraltı Camii.
Köse Bahir Mustafa Pasha converted the cellar into a mosque between 1752 and 1756, with the conversion also dated specifically to 1753. In that year, memorial cenotaphs were added for three holy men at the request of a Naqshbandi dervish, a member of a major Sunni Sufi order. The dervish said that a dream had revealed tombs within the cellar.
The 1754 Istanbul earthquake destroyed the building. Sultan Mahmud I ordered its reconstruction, which was completed in 1756. The mosque’s tower-shaped minaret was later destroyed by an earthquake and rebuilt by order of the same sultan, but the minaret is no longer present. The mosque remains active and is regarded as one of Istanbul’s most visited holy places after Eyüp Sultan.
Remains
Yeraltı Camii retains the rectangular underground structure of the former cellar. Its principal prayer hall and main architectural elements lie below ground level, with vaults supported by 54 thick piers. Natural light enters through windows opened in the wall facing the sea. Two entrances reflect the difference in ground level: one is reached from Kemankeş Street, while the other leads from Karantina Street by stairs.
Underground Rooms and Cenotaphs
Amr ibn al-As and Wahb ibn Husayra
Two underground rooms contain tombs or memorial cenotaphs. The room reached from the Karaköy entrance holds two wooden cenotaphs dedicated to Amr ibn al-As and Wahb ibn Husayra. Their attribution to the Sahaba, the companions of the Islamic prophet Muhammad, is uncertain. Amr ibn al-As, an early Muslim commander and governor, is known to have died in Egypt, and little or no record survives of a Sahabi named Wahb ibn Husayra. Local tradition says that the two men were captured during an attempted invasion of Constantinople and tortured to death. The cenotaphs stand behind an iron grille fitted with glass windows.
Sufyan ibn Uyaynah
A small doorway leads to a central room containing the cenotaph attributed to Sufyan ibn Uyaynah. Local tradition describes him as a soldier serving under Maslama ibn Abd al-Malik, an Umayyad commander and governor, who was captured in battle and tortured to death. Sufyan ibn Uyaynah is otherwise known to have died in Mecca. The room forms a separate memorial space within the underground mosque.
Prayer Hall and Upper Building
The prayer hall includes a minbar and a muezzin’s gallery. Above the underground mosque stands a building with the architecture of a wooden Turkish mansion. It houses the administration of the Sahiller Health Center and was restored in 1985.
The entrance bears the tughra of Mahmud I, the distinctive calligraphic emblem used by an Ottoman sultan on official documents and monuments. This inscription is described as the oldest visible tughra in Istanbul. The former minaret is no longer part of the surviving structure.
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