Here is everything you need to know about the Actun Tunichil Muknal Cave (ATM) in Belize. Trust us, this tour will change your life! There's such a wealth of historical and natural landmarks in Belize that it can be hard to know which to fit into your schedule, but the ATM Cave - or Actun Tunichil Muknal Cave - is a possible contender for Belize's most stunning attraction. Located close to the town of San Ignacio, the ATM Cave is the most popular cave tour in Belize. Its vast network of underground chambers is known as being a treasure trove for archaeologists but also for its diverse ecosystem of bats, crabs, crayfish, and tropical fish. Here's everything you need to know before you start planning a trip to the Actun Tunichil Muknal Cave.

The ATM Cave may today be known as a popular tourist attraction and a great place for caving adventures but the Mayas knew it as the "Cave of the Stone Sepulcher". While ancient historical records are spotty, there's plenty of evidence that Actun Tunichil Muknal has been a sacred site for the Mayas people practically since their origins.

The Mayas first discovered the cave between 300 and 600 AD, but the dark and dangerous environs prevented them from venturing into its deepest realms for quite some time. Somewhere between 700 and 900 AD, the cave had become an important spiritual site for the local peoples. Since what's now modern Belize was once one of the major hubs of the Maya Empire, that makes it one of the critical spiritual sites for one of the most prominent cultures in Mesoamerican history.

And while we may not have a full account of the importance of this cave to the Mayas, modern archaeologists have been able to piece together a fascinating look at their habits and practices in a relatively short amount of time. The cave wasn't rediscovered until 1989, and archaeological investigations prevented it from being made open to the public until 1998.

The first person to explore the cave in modern times was Dr. Jamie Awe, who conducted research there with his Western Belize Regional Cave Project from 1993 - 2000. While it's since become a treasured destination for the most adrenaline-fueled outdoor adventurers, its relevance to anthropologists and archaeologists can't be understated. European colonialism destroyed many of the records of the Maya civilization, and that makes the ATM Cave something of a rosetta stone towards unlocking the customs and traditions of these mysterious people.

The volume of archaeological discoveries in the ATM is truly stunning. Over 1400 human artifacts have been discovered, all of them dating from 250 to 909 AD. The combination of pottery, tools, weapons, and vessels for water tell a tale of a broad and advanced society, and the scope of the discoveries make it one of the most worthwhile finds in archaeological history.

Many of the stories that can be gleaned from the ATM Cave are rather bleak in nature. It's believed that as part of their sacred rituals, the Mayas used Actun Tunichil Muknal to conduct human sacrifices. Well-preserved human skeletons are just as prodigious in the cave as handmade artifacts are, but the most famous of these finds is the "Crystal Maiden".

Due to the passing of time and the unique climate of the caves themselves, this alleged victim of sacrifice has a glimmering appearance that evokes a sense of the supernatural. The maiden herself was found in a main chamber that was believed to be the heart of this makeshift temple, and the presence of "kill holes" further supports the notion that the skeletons found within were the victims of ritual sacrifice.

Other evidence suggests that the sacrificial practices involved significant acts of ritualized torture as well. A Stelae Chamber that serves as one of the centerpieces of most tours contains stelaes where anthropologists believe that victims were placed bound and then bled for the approval of the gods.

Fourteen intact bodies have been found in the main chamber with half of them being children under the age of five. It's believed that young children were favored sacrifices because their purity made them pleasing to the gods.

But not all of the important discoveries are so gruesome. The famous "Monkey Pot" found within the depths of the cave contains a design that's replicated in only three other discovered artifacts, and it's one of the most treasured indications we have regarding the sort of art and craftsmanship that the Mayas indulged in.

Understanding why this cave was of such sacred importance to the Mayas requires an understanding of their spirituality. In the Maya religion, the gods of agriculture, rain, and fertility were believed to reside in the underworld. It would only seem natural that the ATM Cave, with its seemingly endless pits, would be seen as a potential gateway to the underworld. By making human sacrifices within the cave, they could appeal to these important gods practically at their front door.

The cave itself plunges down to approximately four miles, but due to safety concerns, visitors are only allowed about two-thirds of the way down. Visits to the cave have become a popular tourist activity, and any trip with an approved guide is perfectly safe, but you should take some preparations for your own comfort. You are not allowed to visit without a licensed guide. Group sizes are limited to 8 visitors per guide, and a daily limit of 125 visitors are allowed. You should book your tour early to ensure that you secure your spot for your preferred day. You must also be accompanied by a licensed tour guide. Additionally, you guide must be licensed specifically for the ATM cave. There are only about 25 such licensed guides in the country.

Belizeans are serious about preserving the cultural heritage of their ancestors and the majesty of the wild, and that means that access to the cave is largely reserved for foot traffic.

What to Bring/Wear?

Guests should dress as if preparing for a hike, bringing comfortable clothes and sturdy closed toe shoes. You must also wear socks. This is mandatory when you're inside the cave.

Most of all, just keep in mind that you will get wet during your visit. You should bring a small backpack with an extra set of clothes. You'll also want to bring a bottle of sun block able to protect you against the jungle heat and a water bottle to keep you hydrated you throughout the journey. Just make sure it's sealed.

Also bear in mind that no cameras are allowed within the cave. The prohibition of cameras prevents damage to remaining skeletons and artifacts and preserves ATM for future generations.

• Socks (this is MANDATORY)
• Closed toe shoes
• Comfortable clothes
• Change of clothes
• Towel
• Sunblock
• Water bottle

The tour starts with a forty-five minute trek through Tapir Mountain Nature Reserve. It is a great way to soak in the majesty of the surrounding jungle. You will cross three rivers on your hike, pulling yourselves across on ropes. By the time you arrive at the entrance of the cave, you will be soaked.  For a virtual audio experience of this tour, tune in to Episode 20 of The Belize Travelcast.

Your tour through the cave take about three hours on average. Bringing a dry change of clothes for the deeper voyage is advised but not necessary. There's more swimming and climbing (in the dark) to come. If you suffer from claustrophobia, the ATM tour may not be the right fit for you.

There's a reason why tour guides are required for visits to the cave, and it's not just to preserve the skeletons and artifacts contained within. The cave itself is a labyrinth of interlocking chambers, and one can quickly get lost if they don't have someone to provide them with bearings.

The archaeologists and caretakers of this cave have been reverent in its preservation. All of the everyday artifacts were left as they were to preserve things as they were before modern people arrived, and a knowledgeable tour guide can provide you with a fascinating insight into how these people lived.

This is a physically taxing tour, and the combination of tight corridors and pitch blackness can be a challenge for the less resilient, but it's well worth a journey for anyone who's up to the task.

Guests are equipped with headlamps, and reaching the deepest layers of the spiritual cave means venturing through five hundred meters of water. If you can't swim, life jackets are provided. The tours is perfectly suitable for swimmers and non-swimmers alike.

While the most commonly cited appeal for these tours are the human artifacts, the natural beauty of the cave is equally as impressive. The stalactites and stalagmites are often meters in height. The fact that it's taken tens of thousands of years for these formations to develop is a true marvel, and it's no wonder that the Mayas saw the caves as a mystical portal directly to the underworld.

The ceremonial chamber where most of the sacrifices were performed and the Crystal Maiden was discovered is the most humbling landmark within the caves, but it's not the only one. The first notable human-occupied chamber that visitors experience is what archaeologists have dubbed "The Cathedral". While the dark rituals were performed another three hours deeper into the cave, the Cathedral served as something of a waiting area. The urns and stoneware were practical in purpose, used by the shamans in preparation for the human sacrifices that would take place later.

Actun Tunichil Muknal has earned its reputation as one of the most stunning natural and anthropological sites around. National Geographic ranked Actun Tunichil Muknal as the number one sacred cave in the world, placing it above breathtaking spiritual caves throughout India, Greece, and China.

The ATM Cave has to be seen to be believed, and it's not out of the way at all. The close proximity to Maya sites like Cahal Pech, El Pilar, and Xunantunich mean that it can be folded together into a larger tour, but ATM Cave is worth exploring just on its own. The choice is yours, but you should visit Belizing.com before you make your final decision. As the country's largest marketplace for activities, tours, and transfers, Belizing.com is the best resource for getting your bearings and figuring out the best tour options available to you.