Caves are openings in rocks with diameters ranging from five to fifteen millimetres. The Sultanate of Oman's caves—its geological museums hidden beneath the Earth's surface—boast unique characteristics and formations that took thousands of years to form and adorn. They are natural treasures and a national heritage that must be preserved and cared for as an integral part of the Sultanate’s natural and environmental heritage.
Most of the Sultanate of Oman's caves are found in the Eastern Region, the Interior Region, the Dhahirah Region, and the Dhofar Mountains. Among the most famous are Majlis Al Jinn Cave, Al Kittan Cave, Al Hoota Cave, Al Falah Cave, and caves in Dhofar Governorate including Suhur Cave, Hafrat Al Idhba in Tawi Ateer, Ain Hamran Cave (Bat Cave), Wadi Darbat Caves, Marhoof Cave, and Al Mughsail Cave.
The cave can be described as a developed valley or a side branch of a dry river, with its slopes descending towards the riverbed near Al Falah Cave. It descends gradually for a distance before plunging steeply into another slope, resembling a geometric ladder interspersed with lakes. The cave branches into numerous small chambers adorned with stalactites and stalagmites of calcium carbonate, suspended and descending from the rocks.
The temperature inside the cave is pleasant and airy, as the air changes with atmospheric pressure, allowing fresh air to flow from Al Hoota Cave to Al Falah Cave through the lakes. The stalactites and stalagmites dominate the cave's structure, with the most eye-catching feature being the ascending columns. The varying colours of the hanging rocks suggest multiple generations, possibly reflecting different climatic conditions. Some columns reach up to five metres in diameter, with regularly shaped conical columns also present. The descending columns bear witness to cracks in the foundations, where they connect with the cave's ceiling.
The spacious subsidiary chambers in this cave system reveal several hanging rocks and descending columns. Al Hoota Cave, also known to some as Al Falah Cave, represents a significant deposition area. The rocky stalagmites covering the channels are the most striking feature at the entrance, evident at every entrance hall of the cave system. Some of these stalagmites are colossal, reaching approximately ten metres. Some mobile deposits descend from Al Hoota Valley to the cave channel. Additionally, there is some debris settled at the front of the lake, forming a small mound indicative of its dissolution after a major flood.
The cave lake is an extensive body of water believed to stretch all the way to Wadi Tanuf in the Wilayat of Nizwa. It is situated within Al Hoota Cave in Al Hamra, A’Dakhiliyah Governorate. The lake maintains water throughout the year and remains unaffected by seasonal changes. Within its depths live blind fish, typical of cave-dwelling species. Some lack eyes but possess long sensory barbels to locate food, while others have very small eyes. These cave fish, like others of their kind, are pale and lack pigmentation due to living in darkness or low-light conditions. However, they compensate with strong sensory abilities, sometimes developing additional tactile organs on their skin.
The cave is not as primitive as caves from past eras; instead, it features bridges, iron walkways, and paved pathways. Visitors walk through a corridor extending from the cave's entrance, moving safely and comfortably from hall to hall until reaching the water source. The illuminated cave creates an impression of being inside a natural museum of stalactite and gypsum formations, shaped over hundreds of years by dripping water that formed scattered water basins across the cave. Rock pools sculpted by water over thousands of years are also present, reflecting nature’s craftsmanship.
The cave complex includes a reception building housing administrative offices and a miniature museum displaying various rocks and minerals found within the cave. It also features a screening room for documentaries, a waiting area, and the departure point for the train ride. Visitors embark on a train consisting of three carriages, totalling twenty-two metres in length, accommodating up to forty passengers. The train transports them 675 metres into the cave through a mountain tunnel spanning 153 metres. A tour guide explains the cave's different parts and views along a circular path covering approximately 850 metres on foot, with the entire visit lasting about an hour.
Hidden away amid the brown-coloured hills at the foothills of the Eastern Hajar Mountains lies one of the greatest and most spectacular natural wonders: Majlis Al Jinn Cave. It ranks as the third-largest cave chamber in the world.
Experts estimate the cave’s capacity to hold twelve Boeing 747 aircraft or around 1,600 tourist buses. Its impressive floor area spans 58,000 square metres, with a volume of four million cubic metres. The cave measures 310 metres in length and 225 metres in width, with a dome-shaped ceiling rising 120 metres above the floor. Despite its enormous size, it is difficult to spot from the outside amid the vast rugged Najd Mountains, marked only by three small openings that appear hardly noticeable.
Majlis Al Jinn Cave lies at the northern edge of the Salma Plateau near the village of Fanja in the Wilayat of Qurayyat, on the road connecting Dhabab in the Wilayat of Sur with the Eastern Region. Visitors should note that descending or ascending the 120-metre drop requires considerable skill and training, making it unsuitable for beginners. They must therefore take caution and carry the necessary equipment for such a remarkable experience.
The discovery of Majlis Al Jinn Cave was first recorded during the General Water Resources Authority’s programme to study karstic rocks in Oman to explore deep groundwater reserves. The first descent into this enormous cave was made by Don Davidson in 1983 through the 120-metre-deep opening, the shortest of the three. His wife, Cheryl Jones, made her descent in 1984 through the deepest opening, 158 metres deep, which was later named after her. In 1985, Don Jones descended through the third opening.
Reaching the cave’s top requires substantial effort, involving a rugged mountain trail of about 1,300 metres, taking around five hours to traverse. Alternatively, helicopters may be used to bypass the challenging terrain dotted with sharp rocks and undulating plateaus. Entry into the cave can only be made using ropes. Geologists estimate Majlis Al Jinn Cave—also known as Salma Cave—to be about 50 million years old, serving as a remarkable natural repository of geological treasures.
Located in Wadi Nahiz, about 12.5 kilometres north of Salalah, Suhur Cave lies within limestone formations that date back to the early Triassic period. The cave’s entrance opens dramatically over the valley, framed by ancient stalactites resembling natural sentinels.
To reach the main chamber, visitors pass through a narrow northern passage. Inside, the chamber is decorated with magnificent formations—columns and various stalactites, including straw and pointed types—many of which still bear active droplets continuing their slow formation. A distinctive feature of this cave is a dry basin, roughly one metre long and 1.5 metres wide, showing traces of fossilised waterfall markings. Suhur Cave is also home to bats, insects, and other small cave-dwelling species.
Classified as a dissolution sinkhole, the cave reaches a depth of around 211 metres, with a diameter ranging from 13 to 150 metres and a volume of about 975,000 cubic metres, ranking among the largest of its kind globally. It features numerous voids and smaller chambers created by the continuous dissolution of limestone by rainwater and percolating groundwater. The erosion of softer layers between harder strata also contributed to its unique shape. As the sinkhole deepened, pools of water dissolved its sides further, expanding internal cavities.
At its base, several natural pools have formed either from falling rainwater or from groundwater dissolving softer rock layers beneath, leading to the collapse of harder strata. Inside, visitors encounter majestic stalactites and stalagmites, cascading waterfalls, and deep lakes inhabited by rare blind fish. The cave also exhibits vertical fissures descending deep into the limestone.
Its formation was influenced by fault movement, which channelled water underground, eroding the softer rock and forming subterranean passages. The collapse of these passages later created the vast sinkhole. Rock pressure, erosion, and even plant roots nearby contributed to the continued disintegration of the limestone. Ancient carvings of camels and animals on its walls attest to human presence, and for centuries locals used it as a natural water source, renowned for its pure quality.
Today, Tawi Ateer Sinkhole holds significant environmental value, sustaining diverse flora and fauna, including foxes, bats, reptiles, and a rich variety of birds, which earned it the name “Birds’ Well.”
Scientists believe Teeq Sinkhole could serve as a major natural reservoir if its active opening were temporarily sealed during certain seasons, allowing it to store millions of cubic metres of water for the region. However, realising this potential requires detailed geological studies examining fault systems, internal springs, and subterranean tunnels. Current geological data indicates a strong underground connection between the Teeq and Tawi Ateer sinkholes through networks of tunnels aligned north–south and east–west, matching the surface fault lines. The sinkhole sits at the junction of Wadi Thirath and Wadi Shari, enclosed by steep vertical limestone walls.
Situated in the Wilayat of Taqah in Dhofar Governorate, the Wadi Darbat Caves are famed for their spectacular stalactites, some stretching up to two metres. These karst dissolution caves formed through the long-term action of waterfalls and rainwater, which dissolved the limestone either directly on exposed surfaces or indirectly through cracks, creating intricate subterranean chambers.
Six main caves are found in Wadi Darbat, all located in limestone along the valley’s lower slopes. The first cave, on the right side, resembles a natural arch formed by collapsing walls, with a semi-oval entrance 2–4 metres deep, extending about 10 metres inward and positioned 20 metres above the valley floor. Inside are island-shaped stalactites, stalagmites, and flowstones, with a ceiling marked by circular scars of fallen formations. The second cave, 1.5 km from the first, contains ancient carvings depicting camels, goats, and wild animals, evidence of early human use. The third and fourth caves—on opposite sides of the valley—are smaller and similarly adorned with stalactites and stalagmites. The fifth cave, also on the left side, features a semi-dome entrance about 30 metres wide and 20 metres high, its interior gradually narrowing to multiple levels. The sixth cave, the largest, is roughly 80 metres wide and 25 metres high, with extensive flowstones along the floor.
Ecologically, the Wadi Darbat Caves provide an essential habitat for bats, reptiles, spiders, and various bird species. They also hold archaeological importance, with carvings and drawings indicating ancient human activity in the valley.