1. Was it always black?
Did you know the Ka’bah was covered in green and white coverings? Throughout our history it was covered in an array of colours. It’s only from the Abbasid period that a black covering in it entirety was adopted.
2. Did it have any windows?
The Ka’bah used to have two doors; one for entering and the other for exiting. It also had a window on one of its sides.
The current Ka’bah only has a single door, and no windows.
3. When is the door to the Ka’bah open?
The Ka’bah used to be open twice a week. People would enter and pray therein. However, it is now opened only two times of the year for dignitaries and guests, and perhaps for the occasional cleaning.
Watch the doors of the Ka’bah being opened:
4. What’s inside the Ka’bah?
Okay, this is a common question. It is an empty chamber with a few pillars. The entrance door is called Bab al-Tawbah (Door of Tawbah) because fixed onto it are plaques with verses from Surah Tawbah.
Videos depicting the insides of the Ka’bah:

Note: The hatim is part of the Ka’bah. The hatim is a semi-circular wall opposite, but not physically connected to, the north-west wall of the Ka’bah. It is composed of white marble. At one point in time the space lying between the hatim and the Ka’bah belonged to the Ka’bah itself, and for this reason it is not entered during the tawaf. At least many of us can say we’ve been in the Ka’bah… smile
5. The Black Stone is broken?
The Black Stone is surrounded by a manufactured silver casing because it is broken.
Historians differed as to its cause. However, many agree that it was most damaged in the middle ages by an extreme heretical Ismaili group from Bahrain called the Qarmatians who had declared that the Hajj was an act of superstition. They decided to make their point by killing tens of thousands of hujjaj and dumping their bodies in the well of Zamzam.
As if this act of treachery was not enough, these devils took the Black Stone to the East of Arabia and then Kufa in Iraq where they held it ransom until they were forced to return it by the Abbasid Caliph. When they returned it, it was in pieces and the only way to keep them together was by encasing them in a silver casing. Some historians narrate that there are still some missing pieces of the stone floating around.