Sistema Sac Actun

About Sistema Sac Actun

Sac Actun, a mesmerizing natural wonder in the Yucatan Peninsula of Mexico, is the world’s longest underwater cave system. This subterranean labyrinth, discovered in the 1980s, weaves beneath the jungle, concealing hidden chambers adorned with stunning stalactites and stalagmites.

Descend into the cool, crystal-clear waters and venture into the depths, where ancient secrets lie in the intricate passages of this expansive cave network. Sac Actun, meaning “White Cave” in Mayan, is a testament to the Earth’s mysterious underworld, an intricate tapestry of geological wonders shaped over millennia.

Diving into this ethereal realm unveils a surreal world of surreal formations and hidden chambers, creating an otherworldly experience for explorers. As a vital aquifer and archaeological treasure trove, Sac Actun not only presents a unique adventure for those seeking the extraordinary but also stands as a testament to the delicate balance between the surface and the hidden wonders below.

Physical Characteristics

Sistema Sac Actun, a sprawling underwater cave system, extends over 215 miles (346 kilometers), making it the world’s longest. Delving as deep as 328 feet (100 meters) beneath the surface, its intricate passageways and crystal-clear waters harbor a mesmerizing subterranean realm.

Stalactites and stalagmites, formed over millennia, create a captivating spectacle, while unique geological features, like cenotes and chambers, punctuate its labyrinthine expanse. This subterranean wonder, with its astounding dimensions and geological wonders, stands as a testament to the mysterious beauty hidden beneath the Earth’s surface.

Exploring the Sistema Sac Actun offers a journey into the heart of the Earth, where nature’s artistic craftsmanship unfolds in an otherworldly setting.


Nestled beneath the lush jungles of the Yucatan Peninsula in Mexico, Sistema Sac Actun is a mesmerizing underground river system, revealing a hidden world of extraordinary beauty and unique biodiversity. The caves and cenotes that make up this expansive subterranean network are not only a geological wonder but also a habitat for a variety of fascinating wildlife. From the cave-dwelling creatures adapted to the darkness to the vibrant species residing in the surrounding jungle, Sistema Sac Actun offers a glimpse into a mysterious realm teeming with life.

Top 10 Wildlife Species in and around Sistema Sac Actun:

  1. Blind Cave Fish (Astyanax mexicanus):
    • Gliding through the dark waters of Sistema Sac Actun, blind cave fish have evolved to navigate without eyesight. These small, translucent fish showcase the remarkable adaptations that occur in the absence of natural light.
  2. Cave Swallow (Petrochelidon fulva):
    • Darting through the entrances of the underground caves, cave swallows are agile birds that nest in the crevices of Sistema Sac Actun. With their distinctive forked tails, these swallows add a touch of avian life to the cave entrances.
  3. Green Iguana (Iguana iguana):
    • Basking in the dappled sunlight near the cave entrances, green iguanas are reptiles that inhabit the jungles surrounding Sistema Sac Actun. With their vibrant green coloration and impressive size, these iguanas are a common sight in the Yucatan Peninsula.
  4. Mexican Tetra (Astyanax mexicanus):
    • Dwelling in the freshwater cenotes connected to Sistema Sac Actun, Mexican tetras are fish species known for their adaptability to various environments. With their sleek bodies and silvery scales, these tetras navigate the crystal-clear waters.
  5. Bats (Various Species):
    • Flitting through the caverns in the cover of darkness, various bat species call Sistema Sac Actun home. These nocturnal creatures play a crucial role in the cave ecosystem, contributing to pollination and insect control.
  6. Jaguarundi (Puma yagouaroundi):
    • Stalking through the dense jungle foliage surrounding Sistema Sac Actun, the jaguarundi is a small wild cat known for its slender build and reddish-brown fur. These elusive felines are skilled hunters in the Yucatan Peninsula.
  7. Black Howler Monkey (Alouatta pigra):
    • Swinging through the treetops above the cave entrances, black howler monkeys are primates that inhabit the jungles near Sistema Sac Actun. With their distinctive howls and prehensile tails, these monkeys are a charismatic presence in the canopy.
  8. Cenote Cichlid (Cichlasoma urophthalmus):
    • Gliding through the cenotes connected to Sistema Sac Actun, cenote cichlids are colorful freshwater fish. With their vibrant hues and intricate patterns, these cichlids contribute to the biodiversity of the subterranean waterways.
  9. Coati (Nasua narica):
    • Foraging on the jungle floor, coatis are raccoon-like mammals that frequent the areas surrounding Sistema Sac Actun. With their long snouts and bushy tails, these omnivores are skilled at finding food in the forest underbrush.
  10. Red-eyed Tree Frog (Agalychnis callidryas):
    • Resting on the leaves near the cenotes, red-eyed tree frogs are amphibians known for their striking colors and distinctive red eyes. These frogs add a vibrant touch to the surrounding jungles and play a role in the local ecosystem.

Exploring Sistema Sac Actun invites you to uncover not only the breathtaking underground landscapes but also the rich diversity of life that thrives in this unique subterranean environment and the lush jungles that envelop it. From the blind cave fish to the vibrant tree frogs, each species contributes to the intricate tapestry of the Yucatan Peninsula’s natural wonders.

Ways to Experience

Sistema Sac Actun, a mesmerizing underground cave system in Mexico’s Yucatan Peninsula, unveils a hidden world of subterranean wonders. Carved by nature, this intricate labyrinth of caves and cenotes invites adventurers to explore the secrets concealed beneath the Earth’s surface.

Ways to Experience Sistema Sac Actun:

  1. Cave Diving Expeditions:
    • Embark on cave diving expeditions. With crystal-clear waters, Sistema Sac Actun provides a unique opportunity for certified divers to explore submerged chambers, revealing stunning rock formations and ethereal underwater landscapes.
  2. Snorkeling in Cenotes:
    • Enjoy snorkeling in cenotes. Accessible cenotes within the system allow non-divers to witness the beauty of Sistema Sac Actun. Snorkel in the turquoise waters, marveling at the ancient stalactites hanging from cave ceilings.
  3. Guided Cave Tours:
    • Join guided cave tours. Led by experienced guides, these tours offer a safe and educational journey through the system’s chambers, providing insights into the geological formations and the historical significance of the caves.
  4. Underground River Exploration:
    • Explore underground rivers. Navigate through subterranean rivers flowing within the cave system, discovering hidden passages and witnessing the play of light on the water’s surface as it filters through openings above.
  5. Cave Photography Expeditions:
    • Participate in cave photography expeditions. Capture the otherworldly beauty of Sistema Sac Actun with guided photography tours, allowing enthusiasts to document the unique geological features and the delicate balance of cave ecosystems.
  6. Zip Line Adventures:
    • Experience zip line adventures. Some cenotes within the system offer thrilling zip line experiences, allowing visitors to descend into the depths of the cave and admire its mesmerizing formations from different perspectives.
  7. Educational Workshops:
    • Attend educational workshops. Learn about the geological history and environmental importance of Sistema Sac Actun through workshops conducted by knowledgeable guides, fostering a deeper appreciation for this subterranean marvel.
  8. Cave Yoga and Meditation Retreats:
    • Join cave yoga and meditation retreats. Immerse yourself in the serene atmosphere of the caves, participating in wellness retreats that combine the peacefulness of the underground environment with rejuvenating practices.
  9. Birdwatching in Cenote Surroundings:
    • Engage in birdwatching. Explore the natural surroundings of cenotes, where the lush vegetation provides a habitat for diverse bird species, creating opportunities for birdwatching enthusiasts.
  10. Cultural and Historical Tours:
    • Take cultural and historical tours. Gain insights into the ancient Mayan civilization’s connection to the caves, exploring archaeological sites and learning about the cultural significance of Sistema Sac Actun.

Sistema Sac Actun, with its hidden chambers and underground wonders, offers a range of experiences for adventurers and nature enthusiasts alike. Whether diving into submerged caves, snorkeling in cenotes, or participating in educational workshops, each encounter with this subterranean marvel promises a journey into the heart of the Earth’s mysteries.

Best Times

Embarking on an underground adventure like no other, Sistema Sac Actun invites explorers to delve into the mysteries of the world’s longest underwater cave system. Each season offers a unique perspective on this subterranean wonder, promising an unforgettable experience.

Best Time to Visit:

  • Year-Round Exploration:
    • Average Temperatures: Approximately 77°F (25°C)
    • Sistema Sac Actun welcomes visitors throughout the year with a consistent and comfortable cave temperature. This underground realm remains an enticing destination regardless of the surface weather. The caves provide a constant haven for exploration, making any season suitable for those eager to discover the hidden wonders beneath the earth.

Reasons to Visit:

  • Mild Temperatures:
    • Escape the extremes of surface temperatures as you enter the caves, where the stable and mild conditions ensure a comfortable journey. Regardless of the weather outside, Sistema Sac Actun provides a consistent environment for exploration, allowing visitors to enjoy the subterranean beauty without the influence of external climate variations.
  • Unique Underground Ecosystem:
    • Explore a mesmerizing world beneath the surface, witnessing stunning stalactite formations and ancient geological wonders. The cave’s unique ecosystem, with its crystal-clear cenotes and diverse marine life, offers an enchanting experience. Visitors have the opportunity to marvel at nature’s artwork and observe the delicate balance of life within the underground waterways.
  • Avoiding Surface Crowds:
    • Opting for a cave adventure allows you to escape the surface crowds, offering a serene and immersive experience away from traditional tourist attractions. Whether it’s the busy tourist season or a quieter time, Sistema Sac Actun provides a unique and tranquil setting for those seeking a more secluded exploration.
  • Year-Round Accessibility:
    • Sistema Sac Actun’s accessibility remains consistent, ensuring that enthusiasts can explore its passages and chambers without being restricted by seasonal factors. The caves’ accessibility year-round provides a reliable opportunity for adventurers to embark on a thrilling journey whenever they choose.


Sistema Sac Actun beckons year-round with its enchanting underground landscapes and captivating wonders. Embrace the constant allure of the cave system, offering a timeless adventure beneath the surface, regardless of the season.