Video from FTD Facts
The Ka'aba ("the cube" in Arabic) is an ancient stone structure that was built/re-built by prophets as a house of worship. It is located inside the Grand Mosque in Makkah (Mecca) Saudi Arabia. The Ka'aba is considered the center of the Muslim world and is a unifying focal point for Islamic worship. Muslims complete the Hajj pilgrimage to Makkah (Mecca) by circling the Ka'aba. The Quran indicates the Ka'aba was built by the prophet Abraham and his son Ishmael. By the time of Muhammad, the Ka'aba had been taken over by pagan Arabs to worship numerous tribal gods. In 630 A.D., Muhammad and his followers took over leadership of Mecca after years of persecution. Muhammad then destroyed the idols inside the Ka'aba and re-dedicated it as a house of monotheistic worship.
The Ka'aba was damaged several times after Mohammad's death in uprisings and battles, but with each repair, it took on an altered appearance. In 1629, as an example, heavy flooding caused the foundations to collapse, requiring a complete rebuild. The Ka'aba has not changed since then, but historical records are uncertain, and it is impossible to know if the current structure closely resembles the Ka'aba of Mohammad's time.
Muslims do not worship the Ka'aba and itself. Instead, it serves as a focal point among the Muslim people. During daily prayers, Muslims face toward the Ka'aba from wherever they are in the world (this is known as "facing the qiblah"). During the annual pilgrimage (Hajj), Muslims walk around the Ka'aba in a counter-clockwise direction (a ritual known as tawaf). Each year almost two million Muslims may circle the Ka'ba for five days during the Hajj.