You will probably take a shuttle (8-10 hours) from Antigua to Lanquin. One day for Semuc Champey is enough but some people enjoy a second day in the area (relaxing, swimming, tubing, hiking...). We had great weather in January. We went swimming and thought it was great. The water is comfortable. Cool but not cold and as it was warm it was refreshing. My husband hates cold water but had no problem swimming there.
To visit the Candelaria caves this is what we did (in 2011):
We took the 5:30 am bus from Lanquin to Pajal. What an adventure that turned out to be. The minibus was packed and the ayudante pointed to the roof. Apparently we were riding on top of the bus! The road was very bumpy but we very much enjoyed the ride as the sunrise was magnificent. At the Pajal cruce we waited for half an hour for a bus to Raxhuja. The scenery was amazing and the bus was packed. We bought snacks from the vendors who entered the bus at a small town. It was a dirt road, almost all the way to Sebol. In this part of the country we did not see any chicken buses, only minibuses. But they were just as crowded. They stop all the time to let people on and off. The crowds, the vendors, the music, the sales people handing out samples, the dust… it makes for a very interesting ride… and still people sleep (and so did we at times).
In Sebol we waited for 5 minutes for the bus to Raxhuja. Raxhuja is not what I would call a nice town, just one dusty street. We ended up in hotel El Amigo, probably one of the roughest hotels we stayed in. Strangely enough it had air conditioning, a tv and a shower with cold water but the floor was sticky and overall the place was not very clean (Q60 per person).They also had two monkeys on a chain, not something I like to see. Hotel Cancuen looked nicer but we did not see the rooms. We took a pick-up to the Candelaria caves, we got dropped off too soon and walked the rest of the way. We went to the Complejo Cultural and Ecoturistico. There is a lodge there as well and a restaurant, I don’t know how much, it seemed upscale. For Q40 per person a guide took us to the caves (short walk). The caves were nice, very wide and very high, and we liked the light that seeped from the ceiling into the cave, the river and the blue hummingbird we saw. But overall we were not that impressed, the tour was quite short as well. We found a decent comedor in Raxhuja and a restaurant that served fish, nice change. We also went to the church for a bit as a crowd had gathered for gospel singing and to listen to a very animated preacher.
The next day we took a minibus to Sayaxche, a short ferry ride across the river and then another minibus to Flores (for Tikal and Yaxha).
There are other entrances to the caves as well. You can also go tubing in the caves.
I have not been to Laguna Lachua but researched it as we were planning to go. I know you can take a local bus to the entrance and then it is a 4 km walk. You need to take food and water. You can camp there and I think there are a few cabins as well.
