Actun Tunichil Muknal

Actun Tunichil Muknal (often abbreviated as the ATM) is a cave formation in the Cayo region of Belize.

The Actun Tunichil Muknal (literally translated as "Cave of the Stone Sepulcher") is a relatively recent discovery and can be considered to be more of an eco-tourist destination rather than a traditional caving experience. Guides take great pains to stress the importance of Actun Tunichil Muknal as both a natural formation and a site of historical interest.

The cave was discovered in 1992, and was featured on the National Geographic Explorer film, Journey Through the Underworld. Actun Tunichil Muknal represents one of the most well-preserved examples of pre-classical Mayan culture (around 700 - 900 AD), featuring skeletal remains of human sacrifices and scores of Mayan pottery and other ceremonial objects. Since then, the cave has been completely mapped and explored, covering about 5.3 km (3.3 miles).

The cave was opened to the public in 2000, and the artifacts within are in the same position as they were when the cave was explored by researchers. These skeletal remains and Mayan objects are properly demarcated by archeologists and the Belize Tourism Board to prevent damage unwittingly caused by tourists.

Actun Tunichil Muknal lies within the forested limestone hills of the Tapir Mountain Nature Reserve in Cayo District. The surrounding terrain consists of lowland tropical forest growing over porous karst, with sinkholes, underground drainage channels and numerous caves formed as water gradually dissolved the limestone. The archaeological reserve itself covers about 520.8 acres, while the mapped cave system is approximately 3.13 miles long.

A clear stream flows from the cave mouth and continues through much of the underground passage. Reaching the archaeological chambers involves crossing jungle streams, swimming through the entrance pool and then wading through sections of flowing water between narrow rock walls, ledges and large limestone formations.

Farther inside, the passage opens into elevated dry chambers containing stalactites, stalagmites, flowstone and calcite-covered archaeological material. The contrast between the bright forest, water-filled entrance and dark ceremonial chambers is a defining feature of the visit.

The surrounding reserve protects lowland tropical evergreen forest on limestone soils. Vegetation includes tall broadleaf trees, palms, vines, ferns, orchids and bromeliads. Belize Karst Habitat Conservation estimates that Tapir Mountain Nature Reserve may support about a thousand plant species, although only a portion has been documented.

At least 55 mammal and more than 340 bird species have been recorded in the reserve. Wildlife includes Baird’s tapirs, jaguars, pumas, margays, agoutis, pacas, peccaries and deer, although most large mammals avoid tour groups and are rarely seen during a daytime cave excursion. Visitors are more likely to notice birds, butterflies, lizards, frogs and animal tracks along the forest trail.

Bats and other cave-adapted animals may occur underground. Do not shine lights continuously at roosting animals, make unnecessary noise or touch any wildlife. Mosquitoes and biting insects are common along the approach trail, particularly during the wetter months.

The area has a hot, humid tropical climate. Daytime temperatures remain warm throughout the year, while the shaded cave interior and prolonged contact with water can feel surprisingly cool.

Belize’s relatively dry season generally runs from about February through May, while the wetter season extends from approximately June through November or December. September and October are often among the rainiest periods. Tropical showers may be short, but heavy rainfall in the surrounding hills can raise streams rapidly.

High water can make the river crossings and cave passages unsafe. NICH monitors river levels and may suspend visitation when flooding thresholds are reached, so tours can be cancelled at short notice during or after heavy rain.

Although the cave is relatively close to San Ignacio, the only road leading out of the town to the site is a bumpy and rural road that crosses a part of the Mopan River. In any case, a guide is required in order to have access to the caves, so taking a package tour with one of the licensed tour companies in San Ignacio would be the best option. There are also US tour operators who tour the ATM cave. These companies work with local, licensed guides. During Belize's wet season (late June-August), the cave may be flooded and unavailable to travellers.

The cave is located in the Tapir Mountain Nature Reserve. To reach the cave, requires an easy 45-minute hike into the jungle. The entrance to the cave is shaped like an hour glass and is flooded with water. Travelers need to be prepared to get wet, and remain relatively wet to damp during their time in the cave. The cave system consists of a series of chambers, ending at "The Cathedral" where sacrificial ceremonies once took place. Here 14 skeletal remains have been found, and numerous examples of ancient Mayan pottery remain. It takes roughly 1 1/2 to 2 hours to reach "The Cathedral," so travellers should be prepared to be in the cave for 4 to 6 hours. Quick-dry clothing is recommended, as most guides will insist on shorts and a shirt, as a sign of respect. This is a very sacred site. Sandals are not allowed in ATM for safety reasons. Travelers must remove their shoes, and must wear socks while in "The Cathedral" to protect the site from oils on the skin. Guides typically carry a dry pack; however, personal items such as cameras are no longer permitted in the cave due to damage caused by a tourist dropping a digital camera on one of the artifacts. In some locations, the only source of light is from helmets (required for entrance) and/or flashlights. Guides should supply these items.

Actun Tunichil Muknal cannot be visited independently. Every visitor must join a guided tour booked in advance through a licensed tour operator, and entrance tickets must be purchased beforehand through the NICH electronic ticketing system or the ticket office at Cahal Pech Archaeological Reserve.

Groups are limited to a small number of visitors, normally no more than eight people per guide. Children must be at least 40 inches tall to enter. The trip is physically demanding, and operators may decline to accept visitors whose age, mobility, health or swimming ability would create a serious safety risk.

The total tour price usually combines transportation, a specialized guide, archaeological-reserve admission, safety equipment and often lunch or refreshments. Rates differ by operator and departure point, so confirm the full price and inclusions before paying. NICH warns that admission prices and policies may change without notice.

Helmets and headlamps are normally supplied. Confirm whether the operator also provides life jackets, socks, dry bags and drinking water.

The reserve is explored entirely as part of the organized tour. Vehicles travel along a winding dirt road from the George Price Highway to the visitor area, after which participants continue on foot. The approach hike takes approximately 30–45 minutes and crosses three streams or rivers before reaching the cave.

Entering the cave requires swimming across a pool about 6 ft deep, although guides may use an alternative approach for some visitors who are uncomfortable swimming. Inside, the route combines swimming, wading, walking over uneven rock, squeezing through narrow passages and climbing ledges and a metal ladder.

Wear closed shoes with excellent grip and clothing that can remain wet for several hours. Ordinary sandals, flip-flops and bare feet are unsuitable for the approach and water passages. In the principal archaeological chamber, visitors are normally instructed to remove their shoes and continue in socks to reduce damage to the cave floor and artifacts.

Remain close to the guide. The route is not marked for independent exploration, and side passages can lead away from the approved visitor corridor.

The cave’s natural attractions include its underground river, sculpted limestone walls, stalactites, stalagmites, flowstone curtains and large chambers. Headlamps reveal formations gradually as the group moves deeper underground.

The principal archaeological chamber contains ancient Maya ceramics, stone objects and human skeletal remains left where they were discovered. The Maya began using the cave for ritual activities by at least the Early Classic period, approximately AD 300–600, and entered it to communicate with deities and ancestral spirits.

Notable objects include the unusual Monkey Pot, one of only a few known examples of its form in Central America. Many vessels were deliberately broken or pierced as part of ceremonial practices and are now partly cemented to the cave floor by mineral deposits.

The most famous human remains are known as the Crystal Maiden. Their calcite coating reflects the guide’s light and creates a sparkling appearance. Several other skeletal remains lie elsewhere in the cave, demonstrating its prolonged ceremonial importance.

Cameras, phones used as cameras and other photographic equipment are prohibited inside ATM. The rule was introduced after a dropped camera damaged an artifact. Leave such equipment in the vehicle or wherever directed by the operator.

The principal activity is the guided ATM cave expedition, combining rainforest hiking, river crossings, swimming, scrambling and archaeological interpretation. It is a full adventure rather than a conventional walk-through cave tour.

Listen to the guide’s explanation of Maya beliefs surrounding caves and the underworld, the possible purposes of the ceremonies and the archaeological evidence preserved in the chambers. The guide also explains how water and mineral deposits formed the cave’s natural features.

Observe forest plants, birds, insects and wildlife tracks during the approach hike. Morning departures generally offer cooler walking conditions and additional time in case the group moves slowly.

Do not touch pottery, bones, limestone formations or cave walls unless the guide specifically identifies a safe handhold. Never cross ropes, red lines or other archaeological barriers. NICH prohibits removing artifacts, natural material or any other object from an archaeological reserve.

There is no gift store associated with this attraction.

As there are no dining establishments within the preserve; most tours will include a packed lunch, and recommend that you bring along a water bottle and snacks.

Bring drinking water for the journey, although bulky bottles and backpacks may have to remain at the visitor area or in the vehicle. Ask the operator what can be carried through the cave and whether water is provided before and after the excursion.

Do not drink untreated water from the streams, river or cave. Even clear-looking water may contain microorganisms or contamination from animals and land upstream.

The trail, humidity and physical effort can cause dehydration, while hours in cool cave water may conceal how much fluid has been lost. Drink before entering and again after returning to the visitor area.

Alcohol is prohibited within NICH archaeological reserves and should not be consumed before swimming, climbing or caving.

Actun Tunichil Muknal is normally visited as a day excursion, and there is no public visitor lodging at the cave. The majority of travellers stay in San Ignacio, Santa Elena, Belmopan or at one of the countryside lodges in Cayo District.

San Ignacio and Santa Elena offer the widest selection of hostels, guesthouses, hotels, jungle resorts and restaurants. San Ignacio is the normal departure point, approximately a 45-minute drive from the cave approach, before the additional forest hike.

Belmopan and lodges along the George Price and Hummingbird highways are alternative bases. Staying near Teakettle or another community east of San Ignacio may shorten the road transfer, but transport should be confirmed with the selected operator.

Arrange an early breakfast or packed meal with the accommodation, since most tours depart in the morning and occupy much of the day.

There is no ordinary public campground at the ATM archaeological reserve. Camping at the cave entrance, visitor area or elsewhere within the reserve should not be attempted without explicit authorization from NICH and the protected-area manager.

Campgrounds and camping-style lodges are available elsewhere in Cayo District, including around San Ignacio and the Mountain Pine Ridge region. They should be used as accommodation bases rather than as starting points for an independent approach to ATM.

Independent backcountry travel is not permitted as a substitute for the licensed cave tour. The forest contains unmarked paths, rivers, sinkholes and cave openings, while much of the surrounding land is protected or privately managed.

Do not attempt to reach the cave from an unofficial trail or remain in the reserve after the tour. A legitimate specialist expedition, archaeological project or filming activity requires advance authorization from the responsible agencies. Commercial photography and filming also require written permission from the Institute of Archaeology.

As with any cave tour, the best way to remain safe is to comply with guide instructions and to keep with your group, refraining from exploring areas by yourself. As you get deeper into the cave, there is no natural light, and many areas require traversal through chest-high areas of water, as well as short rock formations to climb to get to the main chambers. At no point should you separate from your guide/group.

Additionally, because preserving the pristine nature of the cave - both its natural formations and its Mayan artefacts - is so important, following guide directions closely is a must. Help to retain the undisturbed nature of Actun Tunichil Muknal by complying with guide instructions on acceptable behaviour when exploring the cave. Planning is underway to create more clearly delineated paths in order to avoid inadvertent damage to the cave.

• San Ignacio and Santa Elena — The main regional base, with accommodation, restaurants, markets and operators arranging trips throughout western Belize.
• Cahal Pech — A compact Maya archaeological site on a hill above San Ignacio, with plazas, residential structures and a small museum.
• Xunantunich — A major Maya city reached by a hand-cranked ferry across the Mopan River, known for the tall El Castillo structure.
• Barton Creek Cave — A less physically demanding cave experience usually explored by canoe with a guide.
• Mountain Pine Ridge Forest Reserve — Pine forest, waterfalls, pools and caves northwest of San Ignacio, often combined with Caracol.
• Caracol — Belize’s largest ancient Maya city, deep in the Chiquibul forest and normally reached on a full-day guided excursion.
• Belmopan — The national capital and a convenient base for Guanacaste National Park, St. Herman’s Blue Hole National Park and other inland attractions.