Bimmah Sinkhole: Hawiyat Najm Park, Oman

On the limestone coast of northern Oman, a striking turquoise pool sits inside a natural rock depression known as the Bimmah Sinkhole. Also called Hawiyat Najm, the site lies near the village of Dibab in the Wilayat of Quriyat, Muscat Governorate, close to the coastal road between Muscat and Sur. The sinkhole is surrounded by Hawiyat Najm Park, a landscaped public space developed around the geological feature.

Bimmah Sinkhole, also known as Hawiyat Najm, is surrounded by limestone in northern Oman.

At first glance, Bimmah Sinkhole looks almost too perfect to be natural. Pale limestone surrounds clear blue-green water, while steep rock walls descend toward the pool. Local tradition once linked its formation to a falling meteorite, and the Arabic name Hawiyat Najm, commonly translated as “Falling Star", reflects this connection. Geologists, however, explain

Bimmah Sinkhole: Hawiyat Najm Park, Oman

On the coast of northern Oman, a vivid blue-green pool sits inside a dramatic limestone depression. This is Bimmah Sinkhole, also known as Hawiyat Najm, one of the most unusual natural attractions near Muscat. Surrounded by pale rock and dry hills, the water-filled sinkhole looks almost like a giant natural swimming pool carved into the ground.

The site is located in Quriyat, in Muscat Governorate, near the coastal route toward Sur. A municipal park, Hawiyat Najm Park, surrounds the sinkhole and provides visitors with access to the water by a staircase. The combination of rugged limestone, turquoise water, and the nearby Arabian Sea has made Bimmah a popular stop for travellers exploring Oman's northeastern coast.

Where Is Bimmah Sinkhole?

Bimmah Sinkhole lies on the coastal plain of Quriyat (Qurayyat), southeast of Muscat. Geological research places the feature only a short distance from the coast, within a limestone landscape shaped by groundwater and karst processes.

For travellers driving from Muscat toward Sur, Hawiyat Najm Park is a convenient natural attraction to visit along the way. Recent reporting by the Oman Observer describes the sinkhole as a regular stopping point for visitors travelling to Sur and the South Sharqiyah Governorate. The park is located about 120 kilometres from Muscat International Airport.

Bimmah Sinkhole and Hawiyat Najm

The names can sometimes cause confusion. Bimmah Sinkhole refers to the geological feature, while Hawiyat Najm Park is the landscaped park surrounding it. The Arabic name Hawiyat Najm is commonly associated with the meaning “falling star". That name is linked to a local story that a meteorite created the enormous depression. It is a memorable legend, but it is not the geological explanation accepted by scientists.

First Image credit: Dan

The dramatic limestone depression of Bimmah Sinkhole at Hawiyat Najm Park, Oman.

Image Credit: Flickr

How Was Bimmah Sinkhole Formed?

The spectacular appearance of Bimmah is the result of karst geology. Northern Oman contains extensive carbonate rocks, including limestone. Rainwater and groundwater can gradually dissolve soluble limestone, enlarging underground fractures, cavities, and cave systems. Eventually, the roof of an underground cavity can become unstable and collapse, creating a depression at the surface.

A peer-reviewed geological study carried out near Bimmah identified the area as a karstified limestone landscape and investigated cavities beneath the sinkhole using ground-penetrating radar, seismic refraction tomography and electrical resistivity tomography. The researchers found evidence of subsurface cavities associated with the sinkhole.

A Collapsed Underground Cave

Fieldwork by the Geological Society of Oman gives a particularly useful description of the feature. Its researchers describe Bimma Sinkhole as a collapsed sinkhole and former cave, with the sinkhole occupying an uplifted marine terrace near the coast. Their measurements found a long axis of roughly 60 metres, a width of about 40 metres, and a depth from the surrounding ground to the water table of approximately 20 metres.

This information is important because measurements of Bimmah vary between sources depending on whether they refer to the whole opening, the water-filled area or the depth of the water. For a fact-checked article, it is better not to present one dimension as though every source measures the feature in exactly the same way.

The dramatic limestone depression of Bimmah Sinkhole at Hawiyat Najm Park, Oman.

Image credit: Dan

How Big and Deep Is Bimmah Sinkhole?

Older descriptions commonly give the sinkhole dimensions as around 50 by 70 metres and roughly 20 metres deep. Your original Ritebook article also used those measurements. More recent geological fieldwork measured the opening differently, giving an approximately 60-metre-long axis and 40-metre width, with about 20 metres from the surface to the water table. The different figures do not necessarily mean that one source is wrong. Irregular natural formations rarely have perfectly defined boundaries, and measurements can be taken from different reference points.

Why Is the Water Turquoise?

The intense blue-green colour of Bimmah's water is one of its main attractions. The pool is surrounded by bright limestone, which provides a strong contrast with the water. The geological setting also closely connects with the nearby coast. Research and local descriptions indicate that groundwater and seawater influence the sinkhole's water system. Geological fieldwork has suggested that the water table in the sinkhole is only a few metres above sea level. The Environment Authority of Oman also describes the park's water as highly saline and notes its relationship with the nearby sea and underground passages.

The Meteorite Legend

For generations, a more dramatic explanation has circulated among locals: a meteor supposedly fell from the sky and punched a hole into the limestone. The name Hawiyat Najm itself helps to preserve that story. But there is no need for a meteorite to explain the formation. The geological evidence supports a much more ordinary—and scientifically interesting—process involving limestone dissolution, underground cavities and collapse.

The water-filled Bimmah Sinkhole forms a striking natural landmark in Oman.

Image credit: Dan

Swimming at Bimmah Sinkhole

Bimmah is not merely a viewpoint. Visitors can descend into the depression using the concrete staircase built by the local municipality and reach the water. The sinkhole has become a popular place for a refreshing swim, particularly because the surrounding Omani landscape can be extremely hot. The municipality has developed the area as a park, and recent reporting states that there is currently no entrance fee for visitors. The park also includes facilities such as toilets and a children's play area. Even so, visitors should remain cautious on wet rock surfaces and steep steps. The natural appearance of the pool can make the site look calm, but it is a geological depression with uneven limestone around the water.

A view of the limestone surroundings and water-filled depression at Bimmah Sinkhole.

Image credit: Dan

Hawiyat Najm Park

The park surrounding the sinkhole has transformed what was once a natural geological feature into an accessible attraction. Rather than leaving visitors to approach the depression across rough terrain, the municipality created a managed park, access routes, and stairs. This makes Bimmah Sinkhole particularly easy to include in a wider road trip through coastal Oman. The surrounding landscape is equally striking. The park sits between the Arabian Sea and the Hajar Mountain region, giving visitors a clear sense of Oman's unusual combination of mountains, limestone and coastline.

A Natural Stop on the Muscat–Sur Journey

Bimmah is often visited as part of a journey rather than as an isolated destination. Its position near the road to Sur makes it convenient to combine with other attractions along Oman's eastern coast. Travellers frequently pair a stop at Bimmah with places such as Wadi Shab, Tiwi and the coastal landscapes around Quriyat and Sur. The sinkhole itself can be explored relatively quickly, although visitors who swim may stay considerably longer.

Bimmah Sinkhole forms a dramatic contrast with the dry limestone landscape of northern Oman.

Image credit: Alun W

Frequently Asked Questions

What is the Bimmah Sinkhole?

Bimmah Sinkhole is a large natural depression in limestone near Quriyat in Oman's Muscat Governorate. It contains a striking blue-green pool and is surrounded by Hawiyat Najm Park.

What does Hawiyat Najm mean?

Hawiyat Najm is commonly translated as “Falling Star", a name linked to the local meteorite legend surrounding the sinkhole.

How deep is the Bimmah Sinkhole?

Measurements vary depending on where the feature is measured. Geological fieldwork recorded approximately 20 metres from the surrounding surface to the water table.

How wide is the Bimmah Sinkhole?

Different sources give different measurements. Geological fieldwork recorded an approximately 60-metre-long axis and 40-metre width, while other descriptions give around 70 by 50 metres.

Can you swim in Bimmah Sinkhole?

Yes. A staircase provides access to the water, and swimming is a popular activity at the site.

Is Bimmah Sinkhole connected to the sea?

The geological setting indicates an interaction between groundwater and the nearby coast. Researchers found that the water table in the sinkhole is only a few metres above sea level, while Omani environmental information describes a relationship with seawater through underground passages.

Is the meteorite story about Bimmah Sinkhole true?

The meteorite story is a local legend. Geological studies instead associate Bimmah's formation with karst processes and the collapse of an underground cavity in limestone.

Bimmah Sinkhole lies within a rugged limestone landscape near the coast of Oman.

Image credit: hamitravel

Bimmah Sinkhole: Oman’s Turquoise Natural Wonder

A view of Bimmah Sinkhole, the famous water-filled depression at Hawiyat Najm Park.

Image credit: rcfedersee

Steep limestone walls surround the natural pool inside Bimmah Sinkhole.

Image credit: Jim Newton

The blue-green water of Bimmah Sinkhole contrasts with the surrounding pale limestone.

Image credit: Kashif Pathan

Bimmah Sinkhole: Hawiyat Najm’s Blue-Green Pool in Oman

Bimmah Sinkhole, one of Oman's best-known natural attractions near the coast.

Image credit: Juozas Šalna

Conclusion

Bimmah Sinkhole, or Hawiyat Najm, is one of Oman's most memorable natural landscapes. Its turquoise water, pale limestone walls, and dramatic collapsed form make it look like something created for a fantasy film, yet its origin lies in the slow and powerful processes of karst geology.

The geological evidence points to an underground limestone cavity that eventually collapsed, rather than a meteorite impact. Its exact dimensions vary between sources because the irregular natural formation can be measured in different ways, but geological fieldwork supports an approximate measurement of 20 metres from the surrounding surface to the water table.

Today, Hawiyat Najm Park makes the sinkhole accessible to travellers, with a staircase leading down to the water and basic visitor facilities. Positioned near Oman's coastal road toward Sur, it is an accessible and worthwhile stop for anyone exploring the dramatic landscapes of northern Oman.

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Sources and References

• Sultan Qaboos University / Geosciences: Integration of Geophysical Methods for Doline Hazard Assessment: A Case Study from Northern Oman — detailed scientific research on the Bimmah Sinkhole.
• Geological Society of Oman: The Salma Plateau – Post-mid-Eocene to Quaternary Uplift and Bimmah Karstification — field measurements and geological interpretation of the Bimmah Sinkhole.
• Environment Authority Oman: Hawiyat Najm Park information, including its coastal setting and saline water.
• Oman Observer: Current information on the park, location, and visitor facilities.