The tour starts with a 45min walk through the jungle with a few river crossings. Once we entered the cave and got away from the light he had us hold on to the person in front of us walk in complete darkness. Creepy.
There were all sorts of stalactites/mites and crystals in the rocks that made them sparkle in the light of your headlamp.
Martin had a spotlight and would shine it on things so we could take photos and sometimes the flash worked just fine too. There were entire pots and shards everywhere. Nothing was roped off so you had to be careful in the dark of where you stepped.
We eventually came to the end of the cave tour (the actual cave kept going). We had walked a half mile into a mountain and were under 600ft of earth.
The cave was used for human sacrifices to the gods. The remains of several individuals are strewn about, again with no barriers. You can plainly see the bashed in areas of the sculls and lots of excavation has gone on so there is quite a bit of knowledge.