The giant cave was one of the self-guided ones. You get your helmet and flashlight, and into the abyss you go. Merrily. Lake Cave is a bit special as it got a small lake on the bottom, thriving with pretty unique life, only found in this cave.
Giant cave did become really an experience, as the path through the chambers become harsher and tighter. I say that caves are the perfect place to combine fear of height and claustrophobia. And when the flashlight went off... and didnt turn on, it was nerving. Luckily the helmet had a dim backup lamp, onwards. This happened after climbing up a few ladders in confined space, and crawling through some cracks...
A bit further the only things found were a warning sign and a rope descending into the darkness. Only twenty meters or so down... say ten to be sure;)
Jewel cave was quite nice, but pales in comparison to Giant and Lake.
