The voice

Inside, the cave was perfectly arched smoothly, while the walls and the pavement on the ground were too smooth to be naturally made by nature.

The corridor wasn't high, around 2 meters (6' 7") high, and so narrow that only a single person could barely pass at a time, but not through walking but crawling on both knees and palms.

It made the cave seem like, some rumor of it being cursed may be true. Because it appeared like whoever, lived in there wasn't too big to be a human, and might even be a dwarf, a goblin, or troll. Inside the cave, being outnumbered or surrounded would be a major problem in such an enclosed space especially by short goblins or trolls.

Within the inside of the cave, there was a dark tunnel finely carved which stretched downwards for several hundreds of meters. In the oversight of the cave, a person would be rather shocked and flustered at what they would see.