This is the small cave inside the Dome of the Rock. The small mehrab on the left shows the direction of the Qiblah (i.e. the direction of Makkah).
- This cave has been called ‘The Well of Souls’ (Arabic: Bir el-Arweh) as some believe this is where the souls of the dead gather to wait for the event of Judgement Day. However, this is a myth as is the notion that the rock above it is floating without any support.
Reference: Wikipedia