قريات, Oman
Hawiyyat Najm (Arabic: هوية نجم), known as Bimmah Sinkhole in English, is a water-filled depression, structurally a sinkhole, in the limestone of eastern Muscat Governorate in the Sultanate of Oman, very close to the Al Sharqiyah region just off the highway to Sur, few kilometers before Tiwi.
Listen to the audio guide for Bimmah Sink Hole Free on WIP — starts by itself when you arrive, even with the screen off