Sacred, holy and a religious education place for Clergy men. People living here in order to protect themselves from the Arab attacks they curved the rocks on Karacadağ and made an underground city. It's not possible to see the so often underground curved cities in another Anatolian territories but but Cappadocia which is contemporary.

Ereğli captured by Seljuks had hard days due to cruisidery expeditions.  First passed the Crusaders from here in 1097, followed this Akşehir-Konya-Ereğli by the second crossed army. This army was destroyed by Sultan I. Kılıçarslan in 1107 in the plain of Ereğli. In 1276,  Ereğli was in the reign of Karamanoğulları. Owing to the corruption of Anatolian Unity, it was handed a few times. Particularly The Mongolian Kahatu Khan raided the city in 1291 and killed the men. In 1398, Ereğli captured by Ottomans because Karamanoğlu Alaaddin Bey was defeated by Yıldırım Bayezid. In the ages of II.Bayezid(1448-1512), Yavuz Sultan selim(1466-1520) and Magnificient Suleyman(1495-1566) population raised so new streets and towns founded for civils. Beside economical developments, There also founded new and rich societies. The most important one was “Medine-i Münevvere Vakfı”. The income for this was commonly gathered. Later, It started to lead by Dar-us Sade Land Lords. This continiued till period of Abdulhamit II.

Our famous traveller Evliya Çelebi had been to Ereğli and mentioned about the city like that: “This city is quite nice and has a chief of watering. If there weren't a chief for this bussiness, there exsists a fight each day. There are many garden and widely green areas. The city is located next to Spring of Prophet”