What's the Hajj and are there good reasons for why people worship at the Kabah?

Muslims are required to take a pilgrimage to Mecca in their lifetime, if they have the means to do so.  This pilgrimage is called, Hajj.  It's one of the five pillars of Islam. This is now occurring in Saudi Arabia. 

One of the requirements on this pilgrimage is to visit the Kabah.  It's a squarish black shrine constructed to contain a black stone.  Once at the Kabah, they are required to circle it a set number of times.  The black stone contained in the Kabah is considered by Muslims to be a meteorite, which is unlike other meteorites, because it is viewed to be a gift from Allah.  Its history, according to Muslims, is that it has been connected to Abraham, as well as Adam, and that both of these men venerated the black stone.  Abraham according to Muslims  built the Kabah to house the black stone. 

Question: Where is any of this in recorded history outside of the Qu'ran?  Are there any outside Muslim sources that verify this information?

Muhammad lived from 570-632 AD (CE).  This is far removed from Jesus and his teachings recorded by his selected apostles.   It's far removed from the recorded history of the Tanakh (Hebrew Bible, same as the Old Testament).  There is no mention of the black stone in these earlier writings!  The Qu'ran actually contradicts what was written in the Tanakh and the New Testament, even though the Qu'ran claims that these books are from Allah.  Clearly there is a problem.  The Qu'ran which came after the books of the Christian Bible contradicts those books, yet claims they are from Allah.

How do Muslims get away with this obvious problem?

They say that the Bible was changed, which is why Allah sent his last prophet Muhammad.  The problem is that the Bible hasn't been changed.  It's actually very reliable in its bibliography that we have an accurate depiction of the original manuscripts of the Bible.

Click on OC Apologist's "Why Believe the Bible?" and explore the questions concerning the Bible's accuracy and Jesus' claims to be God, as well as the questions concerning the resurrection.

Since the Qu'ran says that the New Testament is the Word of God, they should read it and take it to heart.  Also, if the New Testament is the Word of God as they claim to be, and I believe it is too, then it can't be changed by men to the point that it no longer remains in its original message and teachings.  That would men that men are more powerful than God if they are capable of erasing his Word to the point that it no longer exists in the way it was given to us by God.  This just cannot happen.  Any Muslim who is honest with his or her faith, must agree that man is not capable of corrupting or destroying the Word of God from existing!