Cehennemağzi Mağarası

Cehennemagzi Cave - Cehennem Ağzı Mağaraları - Entrance to Hell - Heracles Cave - Akheron Caves

Useful Information

Location: Karadeniz Ereğli. Follow Istikbal Cd or Istasion Cd north, where they meet trun right into Cehennem Ağzı Mağaraları Sk.
Classification: SpeleologyKarst Cave TopicGateway to Hell
Light: LightIncandescent Electric Light System
Dimension: L=85 m.
Guided tours: self guided
Photography: allowed
Accessibility: no
Bibliography: H. Aytekin, R. Baldık, N. Çelebi, B. Ataksor, M. Taşdelen, G. Kopuz (2006): Radon measurements in the caves of Zonguldak (Turkey) Radiation Protection Dosimetry, Volume 118, Issue 1, April 2006, Pages 117–121, DOI online
Address: Cehennem Ağzı Mağaraları Sk, Ereğli.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


1998 developed for the public.


Cehennemağzi Mağarası actually has three distinct parts. The first is called Kilise Mağarası (Church Cave) which is a huge entrance chamber with a portal 18 m wide and 4 m high. It is called church cave because according to legend it was used by early Christians for secret masses while the Christian religion was still forbidden. The legend also tells that the sarcophagus of St. Nicholas was once in this cave.

Ayazma Mağarası (Holy Water Cave) is a small cave with a lake inside. The water was considered holy or in Greek hagia (holy) and ma (water). Haya ma became the turkish word Ayazma, hence the name.

And finally, Cehennemağzi Mağarası or Koca Yusuf Mağarası is reached down a narrow staircase in a cleft. It leads down into a dark, 50 m wide chamber with an underground lake and paintings on the walls. This is the actual entrance to the underworld, the name Cehennemağzi or Cehennem Ağzı means Entrance to Hell. It is named after a legend in the old greek mythological text called Anabasis, written by Xenophon. He describes that Cerberus, the three-headed dog which guards the entrance to the Hades, lives in a cave outside Ereğli near Kavakderesi. Herakles aka Hercules, the powerful demigod, entered the underworld through this cave.

The road to the caves follows a small valley, the valley of ancient Acheron. It is also called Valley of the Infidels after an old legend. During Byzantine times a Christian resurrection cult used the caves, which were regarded as Infidels, hence the name. It is not just a legend, as a floor mosaic in the first cave may be seen as evidence of their existence.

All the caves look quite artificial with flat floors and flat ceilings. We are actually not sure if they are natural or artificial. Probably there were some natural erosional caves along the valley which were then used to quarry rocks for the city. Some parts look definitely like a rock quarry.

The caves are located in the city Ereğli, the former Heraclea Pontica, at the northern rim of the historic city center. To find the cave follow Cehennem Ağzı Mağaraları Sk from the place where Istasyon Cd. and Istikbal Cd. meet. The city Heraclea Pontica is a Greek colony on the Anatolian Black Sea coast, at the mouth of the river Lycus. It was founded around 560 BC and named after Heracles. It was the birthplace of the philosopher Heraclides Ponticus.