G-12 Located at the 8th kilometer southeast of the Zonguldak Ankara highway, the length of the cave is 890 meters; It is in the status of a horizontally developed, active, semi-active cave. You can reach the ca ve with a 15-minute walk from the south of Erçek district. Except for the fossil gallery, it is in the active, semi-active zone. There is an underground stream flowing in four seasons in the cave. Erçek Cave, located in the center of Zonguldak, is in the forest and the gigantic mouth of the cave is reached by crossing the pathway surrounded by beech, oak, linden, pine and chestnut trees. The cave is 2 kilometers from Gökgöl Cave. A stream that collects some of the water coming from the Erçek Basin flows into the cave. It is thought that the source of these waters entering the cave consists of sinkholes. The active branch of the cave often zigzags and only requires a small climb in one place, otherwise the cave can be reached on foot. There is a very narrow siphon at the end of this arm. An extremely strong and cold wind blows through this siphon. The stone in the middle of the siphon does not allow passage.

The right arm of the cave goes to the fossil arm. In the fossil arm, although the groundwater is weak, it is seen at the beginning and the large hall can only be reached by crawling. The large hall is rich in travertine, stalagmites and stalactites. When passing from the hall in the fossil arm of the cave to other sections, sandy floors are encountered. All chambers in the fossil arm are closed. One of the remarkable features of this cave is the presence of stalactites in different colors such as white and orange.