The hidden door of Kaaba was revealed when a recent heavy sandstorm hit Makkah during Hajj 2018. And it opened a whole new detail to this hidden thing.
This storm hit the city of Makkah a day before the day of Arafah followed with heavy rains in Madinah. As Hajj pilgrim was getting ready for a ritual called Waquf, it’s when this storm hit Makkah city.
During this storm, an interesting fact came to the public, that it is undisputed that Kaaba had two doors. The storm was so heavy that it fully lifted the black cloth (Kiswa) from Kaaba, and revealed that secret hidden door of Kaaba.
You can clearly see this door, in addition to this, this door was built by Abdullah bin Zubair (RA). In 64 Hijri, when Abdullah bin Zubair (RA) was selected as a Caliph, he built this door as per the directives from Ayesha (RA).
Ayesha (RA) said that it was the wish of Muhammad (PBUH) to have two doors of Kaaba as people could enter from both sides of doors. Due to lack of finance, Muhammad (PBUH) was unable to complete it but Abdullah Bin Zubair (RA) later completed it.
In 75 Hijri, When Banu Ummaiyah again captured the Makkah city under the leadership of Hajjaj bin Yousuf, Kaaba was reconstructed into the shape we see it in today’s age. And then Hajjaj bin Yousuf closed the door, which is also known as the hidden door of Kaaba.
Pieces of this door have been kept in some museums under the Islamic literature section.