The mosque is located on Kırklar Tepesi, which translates to 'Forty Hill,' named after the forty dervishes said to have settled there.
It sits at one of the higher elevations in the Beykoz district, offering natural ventilation and panoramic forest views.
The site is often visited by locals who believe in the 'barakah' or spiritual blessing associated with the hill's history.
It is distinct from larger Ottoman-period mosques, functioning primarily as a parish-level community center.
The Forty Sultan Mosque (Kırklar Sultan Camii) in the Dereseki district of Beykoz is situated on a hill known as Kırklar Tepesi, a location historically significant for local legends regarding forty unnamed spiritual figures. The site functions as a neighborhood mosque while maintaining a reputation as a ziyarat, or pilgrimage site, for those seeking spiritual solace. The architecture follows a modest, traditional Turkish style suited to its hillside placement. Visitors often ascend the path to the summit to observe the surrounding Beykoz forestry and the distant silhouette of the Bosphorus. Unlike the grand imperial mosques of central Istanbul, this site offers a secluded, community-centric environment. The area retains a rural character, distinct from the dense urban core of Istanbul. It serves as a focal point for the Dereseki village community.
The perimeter of the mosque courtyard provides the clearest elevated view of the Dereseki valley and the dense greenery below.
Wear comfortable, sturdy shoes, as the terrain around the hillside site can be uneven.
Combine your visit with a walk through the surrounding Beykoz forest trails for a full afternoon excursion.
Keep a respectful distance from congregants if visiting during prayer times.
Avoid arriving during the busiest times of Friday noon prayers if you prefer a quiet, contemplative atmosphere.
Visitors should dress modestly covering shoulders and knees; women are expected to cover their hair with a scarf; remove shoes before stepping onto the prayer carpet.
