Aventuras Tierra Adentro: One of the Most Extreme (and Fun) Tours in Puerto Rico

One of the most unforgettable experiences in Puerto Rico, Aventuras Tierra Adentro delivers on its promise: an action-packed day of caving, canyoning, rappelling, and all-out adventure in the verdant depths of the El Yunque National Rainforest. If you're up for the challenge, this is a can't-miss excursion that might well have you feeling like an Iron Man by the time you're done.

We met Rossano and Anibal at the crack of dawn at Plaza Colón in Old San Juan. They (literally) rolled out the red carpet for us, and we climbed aboard the van to the tune of the Indiana Jones theme song.

As we drove out of the city on the way to the El Yunque National Rainforest, Rossano and Anibal treated us to one of the cheesiest, self-deprecating, at times highly colorful and full-spirited orientations you're ever going to get from an adventure tour company. Quite a few of their jokes can't be repeated here (although, to be fair, we were all adults on the trip), but I'll give them full marks for their energy, attitude, and friendliness.

In between the gags and the interesting info on the rainforest valley and subterranean river that was our destination, Rossano stressed two guiding themes that would govern our day: teamwork and safety. This was no leisurely jaunt into the forest; this was high-energy, extreme sport. And we were warned that it wasn't for the faint of heart.

After a brief stop at a local panadería to grab a strong cup of coffee, breakfast sandwich and bathroom pitstop, we packed our gear and a light lunch into the backpacks Rossano had provided for us. We reached our starting point, and our guides proceeded to take us through the basics of the exercises we were going to attempt. While learning rappelling techniques, how to use rope, harness and carabiner (the steel loop with a sprung), and mastering all the gear we were going to lug around. It took about three seconds to get mud-splattered, sweating, and excited about the adventure.

And then we set off, hiking down a rough trail to the first of a few zip-liness. One of the highlights of the morning was rappelling into the open air (as opposed to the more common version of rappelling down the side of a cliff or mountain) down to the mouth of the world's third largest subterranean river. But that, as it turned out, what just the beginning.

[A word here about why it's good to be with the pros: just a week before, two adventure junkies died while caving nearby on their own. Even if you're experienced at this kind of thing, I recommend going with these guys; they are widely considered the best in the business on the island.]

Swimming against the current in the river, trekking through caves (with some wicked-looking but harmless spiders along the way), and even zip-lining into the dark open, was an incredible rush. And after we got out, we got to via ferrata (which is Italian for "road with irons") our way back up the mountain. With Rossano's tips in mind, it was a breeze, and one of the best activities of the day.

I have to confess, two of our group were injured during the trip, which goes to show that Aventuras Tierra Adentro is for those who don't mind taking a few risks. But it was also, without a doubt, the most exciting and rewarding tours I've ever taken. And when I made it across the finish line (Indiana Jones theme song blaring through the speakers), I felt amazing.