You walk up to the patch of bare rock surrounding a cave that leads into the wooded hillside. The road is just below. The sound of slow, deep, rhythmic breathing issues from the cave, which is quite wide, and just tall enough to walk into without stooping.
Your attempt to peer into the darkness is broken as a huge, green serpentine head pops out and looks at you. "What are you waiting for?" the dragon rumbles. "Come on in!" It withdraws as quickly as it came.