The Kaaba, a cube-shaped stone monument in Mecca, Saudi Arabia, is the holiest site in Islam. The exterior is covered by a curtain of black silk and gold called the kiswah. Access to the interior of the Kaaba, which contains Qur’anic inscriptions, is extremely rare. The Kaaba’s eastern cornerstone is known as the Black Stone, a relic traditionally dated to the life of Adam and Eve. Islamic tradition holds that Adam built the first structure on earth in the spot the Kaaba now occupies. The prophet Ibrahim (the biblical Abraham) and his son Ishmael rebuilt the Kaaba on the foundations left by Adam. The Kaaba served as the site of a major pilgrimage for pagan Arab tribes until 631 CE, when the prophet Muhammad rededicated it to Islam and made it a central component of the obligatory hajj pilgrimage. The Kaaba is now housed within the Masjid al-Haram, also known as the Sacred Mosque, the largest and holiest mosque in the world.
The Kaaba serves as the qibla, the direction that all Muslims across the world face during prayer. It is the holiness of the Kaaba that makes the Sacred Mosque the holiest of all mosques and Mecca the holiest of cities in Islam. Its strong association with the prophets Ibrahim and Muhammad inspires great reverence among Muslims. As part of the hajj, pilgrims are required to perform the Tawaf, a ritual in which they circumambulate the Kaaba seven times. The circumambulation of millions of Muslims around the Kaaba during the hajj represents the unity of believers in worshipping God, and has become an iconic symbol of Islamic piety. During the Tawaf, Muslims kiss the Black Stone (or simply point at it if it is too crowded) each time they pass it in accordance with an Islamic tradition holding that Muhammad kissed the Black Stone during his hajj.