Bimmah Sinkhole is a natural karstic collapse filled with turquoise water, located on Oman's east coast between Muscat and Sur. Carved into limestone through dissolution and erosion, it forms a natural pool roughly 40 meters long and 20 meters wide. Fish swim freely in its brackish waters—a blend of fresh water and seawater. The site has been developed as a public park under the name Hawiyat Najm Park.

Essential Information at a Glance

• Admission: Fee-based (modest tariff; public park managed by local municipality)
• Swimming: Permitted — bring a swimsuit
• Recommended duration: 30 to 60 minutes
• Access: Car recommended; the site is visible from the coastal road (Route 17) between Muscat and Sur
• Dress code: Appropriate swimming attire; women may swim in covering clothing
• Facilities: Changing rooms, toilets, and access stairs to the water are available on-site

What to See

The sinkhole opens into a limestone plateau a few meters from the shoreline. The water, an intense blue-green, is remarkably clear. Hundreds of small fish—mainly mullet and goatfish—move about the swimmers. The rock walls drop sharply for several meters. Concrete stairs allow descent to the water's surface.

History and Context

The local term hawiyat najm roughly translates to "fallen star" in Arabic, with popular legend attributing the sinkhole's formation to a meteor impact. Geological reality is karstic: water dissolved limestone over millennia, causing the collapse of an underground cavity's ceiling. Proximity to the sea explains the intrusion of saltwater into the basin.

Highlights of Your Visit

Swimming in the Sinkhole

Descending the steps and plunging into this sunken natural pool remains the core experience. The water is cool even in summer; fish approach without hesitation. Depth varies by zone; the edges are accessible on foot.

Fish in Their Natural Habitat

Aquatic life is visible to the naked eye from the stairs. Some visitors bring bread to attract fish, though this practice is discouraged to preserve the ecosystem.

The View from the Rim

From the sinkhole's edge, the contrast between beige rock and turquoise water is striking. Mid-morning light shines directly into the depths.

Photography Tips

Best light occurs mid-morning, when the sun is high enough to illuminate the sinkhole's interior without backlighting. From the upper rim, a wide-angle lens captures the entire basin and rock walls. Descending the stairs, reflections on the water and the fish photograph well with a waterproof smartphone or protected camera. Avoid peak hours (midday on weekends) for crowd-free images.

Location and Access

Bimmah Sinkhole sits on Route 17 (east coast), approximately 120 km southeast of Muscat and about 90 km north of Sur. The site is signposted from the main road. Parking is available at the park entrance. No regular public transport serves the site; car rental or an organized tour remain the most practical options.

Local agencies in the Nomadays network often include this site in a one or two-day Muscat–Sur circuit.

Nearby Attractions

• Wadi Shab — spectacular gorge with natural pools and waterfalls, about thirty kilometers south.
• Wadi Tiwi — lush valley with hilltop villages, immediately near Wadi Shab.
• Qalhat Ruins — medieval port city, UNESCO-listed, on the road to Sur.
• Sur — coastal town renowned for its traditional dhows and fort, approximately 90 km south.
• Fins Beach — white sand beach between limestone cliffs and turquoise sea, a few kilometers south.