The Holy of Holies is a term in the Hebrew Bible that refers to the inner sanctuary of the Tabernacle, where the Shekhinah appeared. According to Hebrew tradition, the area was defined by four pillars that held up the veil of the covering, under which the Ark of the Covenant was held above the floor. According to the Hebrew Bible, the Ark contained the Ten Commandments, which were given by God to Moses on Mount Sinai. The first Temple in Jerusalem, called Solomon's Temple, was said to have been built by King Solomon to keep the Ark.
A model of the Tabernacle showing the holy place, and behind it the Holy of Holies
Depiction of a Jewish High Priest wearing Hoshen and Ephod included as an illustration in a Christian Bible; the Holy of Holies is in the background (1890, Holman Bible)
Model of the Second Temple
The Magdala stone
According to the Hebrew Bible, the tabernacle, also known as the Tent of the Congregation, was the portable earthly dwelling used by the Israelites from the Exodus until the conquest of Canaan. Moses was instructed at Mount Sinai to construct and transport the tabernacle with the Israelites on their journey through the wilderness and their subsequent conquest of the Promised Land. After 440 years, Solomon's Temple in Jerusalem superseded it as the dwelling-place of God.
Model of the tabernacle in Timna Valley Park, Israel
The tabernacle, engraving from Robert Arnauld d'Andilly's 1683 translation of Josephus.
Tabernacle Tent dimensions according to the Book of Exodus
Tabernacle Tent and Courtyard dimensions according to the Book of Exodus