Black Stone

The Black Stone is a rock set into the eastern corner of the Kaaba, the ancient building in the center of the Grand Mosque in Mecca, Saudi Arabia. It is revered by Muslims as an Islamic relic which, according to Muslim tradition, dates back to the time of Adam and Eve.The stone was venerated at the Kaaba in pre-Islamic pagan times. According to Islamic tradition, it was set intact into the Kaaba's wall by the Islamic prophet Muhammad in 605 CE, five years before his first revelation.

Source: Wikipedia