Exploring a cave is called spelunking. A trained person who explores and respects the cave is a caver. Never go into a cave without someone who knows what they're doing. Never go into a cave alone. You also need the proper safety equipment to explore a cave. When touring a cave, never go into closed and unauthorized areas.
One never knows what cave critters and other dangers might be lurking in the darkness.

AT YOUR OWN RISK! 

CRITTER CAVERNS