Modern Ereğli is the home of Erdemir, Turkey's largest steel plant. It has a large natural harbour, located in the lee of Baba Burnu and therefore one of the few geographically attractive places for a harbour on the western Black Sea coast of Turkey. Ereğli is a very lively coastal town, well developed due to the presence of the steel plant. Fishing is a major commercial activity in addition. Because of its Black Sea beach, Ereğli is a popular tourist destination locally. The city does not have an airport (Erdemir has a small private field) or rail station, but can be reached by automobile or bus from Ankara, Istanbul and other places.
Aside from fishing and steel, Eregli is also well known for its delicious Ottoman strawberry.
The discoverer of the northern Turkish coalfields, Uzun Mehmet, lived in the Kestaneci Köyü ("Chestnut-seller Village") section of Ereğli.
The city was a Greek city in ancient times known as Heraclea Pontica after the Greek mythical hero Heracles. The Turkish name Karadeniz Ereğli means "Black Sea Ereğli" (kara="black", deniz="sea"), which distinguishes it from other places called Ereğli (the name Ereğli derives from Heraclea) . It was founded by a Megarian colony, which soon subjugated the native Mariandynians and extended its power over a considerable territory. The prosperity of the city, rudely shaken by the Galatians and the Bithynians, was utterly destroyed in the Mithridatic Wars. It was the birthplace of Heraclides Ponticus. According to Greek mythology, the cave guarded by the three-headed dog Cerberus is located near the town. For his final quest, Heracles is tasked with entering the cave and capturing Cerberus.