Lanquin is a small little village about 6 hours from Guatemala City and Semuc Champey another 25 minutes in the back of a pickup truck. There are not a lot of travellers there at all, but the ones who make the trip all come to see the Grutas de Maria and Semuc Champey. This area is all about water - perfect for me.
The hostel I stayed in was in a gorgeous area, with green sloping grass and tropical plants down to a blue river for swimming. The each little cabin was on a platform and was constructed with wood and palm leaf roofs.
This part of Guatemala is limestone and has a lot of karst features. The Grutas de Maria is a cave system that you tour with a guide. It is partially full of water, so there is lots of swimming, climbing up waterfalls, and jumping down 10 feet off rocks - all inside of a cave with either a headlamp if you were smart enough to bring one, or a candle supplied by the guides. I don't have any pictures from inside the cave, as my camera is not waterproof. I am hoping that I will get some by email from some other travellers.
After the caves, I visited Semuc Champey. This is an area where the Lanquin river flows underground for about 300 m, exiting in over a waterfall. We climbed up inside the waterfall and jumped in to the pools beneath. Above the area where the river flows underground is a relatively flat section of limestone, filled with small, turquiose and green pools of water, each cascading down to the next in a small waterfall. The view from the Mirador, complete with howling howler monkeys is fanciful and swimming in the pool feels otherworldly. If you closed your eyes and pictured the perfect jungle paradise of rivers, waterfalls, trees, animals, this is it. And there were only 15 people in the whole area all day.

Hiking at Semuc Champey
View of Semuc Champey from the Mirador
The area where the river goes underground and the start of the pools on the left.
Close up of the pools