EL PASO – As it rains, explorations begin in a cave big enough for persons to stand. Darkness in the middle of the cave eventually leads to light at the other end. Outside, huge boulders loom. Climbing the rocks and crawling through crevasses in the caves that tunnel through the boulders leads to open spaces and the discovery of new caves at Hueco Tanks State Park. When it rains, the holes fill up to create little waterfalls that flow into one another and create babbling brooks around the area.