The Temple Mount is a complex historic site. Traditionally the site of Solomon's Temple, it later housed the Second Temple before being destroyed by the Romans. King Solomon was the son of David and his temple was built at the dawn of Judaism in 1000BC.
Prior to its destruction, the temple housed the Ark of the Covenant, which contained the tablets of the 10 commandments. It also marks the site where Abraham was asked to sacrifice Isaac.
The rise of Islam saw the Arabs sweep into Jerusalem in 630AD and seize the Temple Mount. The Dome of the Rock was built a few years later, on top of the old temple site. It was one of the first and finest achievements in Islamic architecture. Intended to proclaim the superiority of Islam, the majestic gold-domed building remains a letterhead of Jerusalem.
For Muslims, the Temple Mount is a sacred site because it was from here they believe Muhammad left the Earth on his Night Journey.
Judaism's most sacred site is the Western Wall. The towering stone-slabbed wall is the only surviving piece of the Second Temple. After the Arabs seized control of Jerusalem, Jews were banned from accessing the Temple Mount, and this wall was the only part of the ruins they were allowed to approach, hence why it is often called the Wailing Wall. Non-Jews are allowed to approach the wall, although decorum is expected at all times.