My husband and I did the ATM tour in March 2012. We decide to do it based on the reviews which were very accurate. You have to walk/hike quite a bit and cross the river 3 times to get to the cave. Merely shoes that can go in water are useful and you do need socks for inside the cave. The tour is great, exciting, interesting and very much worth it. It does take almost the whole day. The crystal maiden is inside which is amazing. There is a lot of Mayan pottery as well. You do need to go with tour I think we used BZM which we booked ourselves just by walking into San Ignacio ourselves. Great prices much cheaper than through the hotel.
If you own or manage ATM Cave Tour, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.