The building group named after Eşrefzade today consists of a mosque, a burial chamber containing eleven sarcophagi adjacent to it in the west, the building of charity for religious officials and a minaret in the northwest, separate from the mosque. The mosque, which was destroyed by the Greeks during the War of Independence, was rebuilt in 1950 in similar dimensions to the original. Information about the construction date of the mosque is contradictory. It is generally accepted that it was built in 1518 by Mükrime Hatun, wife of Şehinşah, one of the sons of Bayezid II. It is seen that the minaret is similar to the Çandarlı Hayrettin Pasha and Ali Pasha mosques in Iznik in terms of construction technique. The mosque and mausoleum are dated between 1469, the date of death of Eşrefzade, and 1518, the date of Mükrime Hatun's death. The minaret to the west of the mosque has an octagon base, a dodecagonal body and a single balcony. It is decorated with six stalactite rows and consoles, and the body is decorated with five rows of tiles at approximately 1 meter intervals.

It is thought that the sarcophagi located in the west of Eşrefzade Mosque were located in the tomb that was destroyed by Greek soldiers in 1922, the tomb was with portico, wooden pillar, eaves and covered. Eşrefzade Addullah, who went to Ankara from Iznik with the advice of Emirsultan and became the disciple of the Hacı Bayram-ı Veli; He married Rümi Hacı Bayram's daughter named Hayrünnisa and returns to İznik as the caliph of the Bayramiye Sect. Later he went to Hama city in Syria. There, he entered the ruling sect of Sheikh Hüseyin Hamevi, one of the grandchildren of AbdülKadir Geylani . When he returned to Iznik, he established the Esrefiye branch of the Kadiri Sect. Eşrefiye Sect is the most common sect in the Ottoman geography, especially in the Balkans. It is known that Eşrefoğlu Rumi wrote hundreds of works and raised many followers in his lodge.