Let me just say, these two sites are extremely underrated in the guidebooks on Guatemala! Everything I read barely glanced over them, but these are a must see, trust me!
Finca El Paraiso
This is a hot waterfall...yes hot, painfully hot at the top, actually. But don't worry, you won't have to touch that part. First things first, you can visit both these sites from Rio Dulce, you should visit both in the same day, and the whole entire thing including all transportation and entrance fees is about 70Q, around $9! Insane.
Grab a collectivo from town. You'll most likely be dropped off at the Sun Dog Café when you get into Rio Dulce, and they can tell you where to get the collectivo. But ask any collectivo driver, and they will help you out. The ride is about 10Q.
They will take you to your first stop which is the hot waterfall. You'll pay an entrance fee of 5Q. You'll walk back through the woods along a river which flows from the waterfall. You'll begin to smell the sulfur. Once you arrive at the waterfall, you can drop your things off to be watched by the guard. The guard can also help you explore the many wonders of this waterfall including the cave, jumping off from the top, and the white lava mud bath!
Swim around and play at your leisure, make sure to find the creepy small cave. When you are ready, ask the guide to take you to the white lava mud. You'll crawl up an awesome steep path, using vines to help, to reach the top of the waterfall. Up top, the water is nearly boiling, and not safe to stand in. You'll walk back a ways into the woods and the guard will disappear further back, and come back with a ball of white mud. He'll use the hot water to thin the mud and lather it all over your skin for a natural spa day. Later, when it comes off in the water, your skin will be baby soft. This experience was so fun!
When we were done, the guide brought us back and showed us where we could jump from the top (video here) of the waterfall back into the water. Sadly, we were the only ones of about 15 people there who took advantage of this whole tour! Everyone missed out on the jumping and the mud because they didn't want to make the climb. So make sure to ask the guard!
Once you're done, head back out to the road, and jump on the next collectivo to El Boquerón. It should be about 10Q.
El Boquerón Canyon
This was so $#%! cool. And you know what's crazy? Everyone I spoke to said I could miss it, that it was nothing that special. But that's because they didn't go deep enough into the canyon! Yes you can just pay the entrance fee (10Q) and just take the 10 minutes boat ride into the canyon until your young guide drops you off onto the "beach" (15Q)....but what no one will tell you is that if the water is low enough, you can walk deep into the canyon! Hours into it in fact!
WARNING: This is NOT a guided tour. No one goes back there with you. Sometimes the water is deep enough that you must swim. You will be swimming against currents, climbing over rocks, etc. It was exhilarating, but at times a little frightening, and I did wonder if we didn't return if anyone would even come looking. With that being said, if you are careful, this is a stunning experience.
We ended up adventuring in about an hour until we got to a point where we couldn't figure out a safe way to keep going so we went back. It was amazing to be alone (well me and my boyfriend), nothing with us, our belongings left in the canoe with the boy who dropped us off, swimming, walking, looking up at the high canyon walls, wondering if anyone or anything was around us. My boyfriend, who has been skydiving (something I would never do...I think) said adventuring deep into the canyon was the craziest things he'd ever done.
Overall, well well worth it!
The ride back into town is about 20Q and there you have it! If you are in Rio Dulce, do not miss these amazing sites!