

MUSCAT: A dramatic stretch of limestone cliffs, ancient caves and towering mineral formations in southern Oman has earned a spot among the world’s most significant geological landmarks.
The International Union of Geological Sciences (IUGS) has officially inscribed the "Karst Landscapes and Tufa Deposits" of the Dhofar Mountains onto its third list of the Top 100 Geological Heritage Sites, placing the region alongside global icons like Japan’s Mount Fuji, the Norwegian Fjords, and California’s San Andreas Fault.
The announcement was made on November 6 in Loulé, Portugal, during a gathering hosted by the Algarvensis Geopark that brought together 156 earth scientists from 49 countries.
For Oman, the listing is more than just a scientific accolade; it is a major boost for the country's growing geotourism sector. Selected from a global pool evaluated by over 1,000 experts, Dhofar is one of only six sites in the Middle East to make the cut on the 47-country list.
Dating back to the Neogene and Quaternary periods, the Dhofar range offers scientists a rare, open-air laboratory where two massive forces of nature—tectonics and climate — collided to shape the earth.
Millennia ago, the tectonic opening of the Gulf of Aden pushed ancient Precambrian rocks and overlying limestone upward, creating a high plateau. Today, that plateau drops off sharply in the south, forming sheer cliffs rising more than 1,000 metres above sea level — some plunging straight into the Arabian Sea, others framing the 20-kilometre-wide coastal plain around Salalah.
Over time, seasonal rains dissolved the limestone, carving out a rugged terrain riddled with sinkholes, deep wadis and hidden caves.
What truly sets Dhofar apart, according to the IUGS dossier, are its massive calcareous tufa barrages—natural dams built up over thousands of years as mineral-rich spring water deposited calcium carbonate across valley floors.
The crown jewel of these formations is the Wadi Darbat barrage. Stretching roughly 800 metres across and towering over 100 metres high, it is a geological marvel that the IUGS notes has no equal anywhere else on the planet. Formed during wet climatic phases in the Middle Pleistocene, several of these formations still come alive every year during Dhofar’s famous Khareef Dhofar Season.
While geologists initially flocked to Dhofar to study how the Arabian and African tectonic plates drifted apart, modern researchers are increasingly looking inside its caves. By analysing mineral deposits and tufa layers, scientists are piecing together how the region’s climate shifted over the last several hundred thousand years — work that also sheds light on how early humans lived and migrated through southern Arabia.
"The scientific value of the Dhofar Mountains lies in the fact that they combine the impact of tectonic processes and climate in a single location," said Dr Mohammed bin Hilal al Kindi, Chairman of the Earth Sciences Consultancy Centre in Muscat, who co-authored the nomination alongside lead researcher Dr Andrea Zerboni of the University of Milan and an international team from Italy, France, and the US. "These mountains are an open-air natural laboratory for Earth sciences."
Officials say the recognition validates years of efforts to spotlight the country's natural wonders alongside its cultural monuments.
"Heritage is not limited to what humans have built; it also encompasses what nature has crafted over vast geological eras," said Eng Ibrahim bin Said al Kharousi, Under-Secretary of the Ministry of Heritage and Tourism for Heritage. He added that the ministry plans to leverage the listing to draw researchers and travellers alike while strengthening conservation efforts to protect the fragile landscapes for future generations.
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