Walking into an elevator with only two buttons the ranger presses lobby, the LED numbers start to tick by on the display above us. 750...500...250...50...finally the doors open and bright light rushes to our pupils for the first time in hours. We had just spent the whole morning exploring Carlsbad Caverns National Park in New Mexico, and those numbers counting down were not the standard floor numbers you see in most elevators, they were the number of feet we were underground.

As you walk the switchbacks into the dark mouth of the caverns you can't help but wonder about the first person who stumbled upon this hole in the Earth. And if you stay until sundown and watch the half a million free-tailed bats exit the cave you will definitely question who had the guts to enter with nothing more than the light from a lamp.

Once you actually get over the shock factor of entering the Earth you are immediately greeted by monstrous stalagmites and stalactites. They hang from the ceiling and seem to stand like giants on the ground, their sheer size is indescribable; even pictures don't truly convey the scale at which they exist in Carlsbad. Everywhere you turn your head there is another spectacular geologic formation or reflective pool strategically lit up by bulbs placed in the cave by the national park service. If you're a photographer be prepared to fill up your memory card, I actually had to tell myself to stop taking pictures or else I could have spent the whole day down there.

As a general visitor you can still spend hours exploring the paved paths that crisscross throughout the caverns. If you are a little more daring you can pay an extra fee ranging from $7 to $20 and actually make your way into some of the deeper portions of the cave. If you opt for one of these guided tours be prepared to crawl on your hands and knees through some pretty tight spaces. But don't worry: you will be supplied with elbow and knee pads along with a helmet.

Perhaps the most astonishing part of it all is that the national park service still has not seen the deepest depth of Carlsbad. They are constantly finding deeper and deeper passageways and the park keeps growing. A reminder that there are still untraveled paths and unexplored corners of this great planet.