The shrine and masjid located in the Dereseki village of Beykoz was built by Fernarizade Muhyiddin Efendi, one of the Sheikh al-Islams of Selim III.’s era.
Kırklar Sultan was a holy person from the lineage of the Prophet Muhammad. His tomb was discovered in Suleiman the Magnificent’s era. Kemal Efendi one of the sheikhgs of the time discovered its location. Legend has it that Kırklar Sultan is a miracle worker, that he can read people’s thoughts, that he has the knowledge of “Ledun” and is one of Hızır’s students. Voluntary people clean and maintain the tomb every day in rotation. The visitors of the shrine increase in holy days, nights and months.
Beykos is also home to many Shrines such as the Last Martyrs Shrine, the shrine of the saint called the Tall Saint, but whose real name is Omer Halveti; Gazi Yunus shrine in Yalıköy, the Şemsi Sultan tomb in Dereseki Village Cemetery, the shrine of Sheikh Abdulhakim Bukhari Efendi i the Akbaba Can Feda Hatun Mosque, Kavak Hasan Dede in the Anadoluhisarı cemetery, Iskender Paşa adjacent to the mosque in Kanlıca of which he was the bnefactor, Cretan Sheikh Selim Efendi in the Göksu cemetery, Serbostani Shekih Edhem Efendi i the cemetery of the lodge called by his name in Yalıköy, and the Çakmak Dede shrine in the cemetery established to his name.