I don't know what company we used as it was arranged by my friend. I think our guide was one of, if not the very first to be allowed to take tours through it. I'm thinking is name was Ericqo or Enrique. He was *very* good. The hike in is about 45 minutes on a trail, that can get a bit slippery when wet. You wade through the same stream 3 or 4 times as it curves around the trail. At the mouth of the cave, you have to swim about 15' through 15' or so deep of water to get to the ledge just inside the cave. Once inside, you will be doing climbing, crawling, wading and lots of hiking. There was just one bit that gave me a touch of claustrophobia. I had to twist my body through a small opening but many others had gone before so I knew it would be OK and I was through before I knew it. Once inside the cave it took around 4 hours.
Be sure to wear quick dry clothes. I just wore biker-type exercise shorts and a 3 quarter lenght sleeve t-shirt, to keep me from scrapes and stuff. However, while that worked great to keep me from being scraped and I was quite comfy for doing the work, I got chilled especially afterwards.
A fish and a bird can fall in love, but where will they build their nest?