The Torah is kept in the Aron Ha-kodesh (the Holy Ark). The ark found in a modern synagogue is reminiscent of the ark in which the Israelites kept the Torah which, according to tradition, God gave Israel through Moses on Mount Sinai. The Ark of the Covenant was a wooden box overlaid with gold, which the Israelites carried with them throughout their 40 years of wandering in the wilderness, and then brought to the Land of Israel where it was kept at the religious center in Shiloh. King David brought it to Jerusalem, amidst a procession including music and dancing, when he made the Holy City his capital. After King Solomon built the Temple in Jerusalem, the ark was installed in the Holy of Holies, the inner sanctuary, of the Temple.
The Aron Ha-kodesh resembles a closet or cabinet, in which the Sifrei Torah (Torah scrolls) are housed. A Ner Tamid (eternal light) hangs outside and above it. Its opening is protected by a curtain called a parochet, because the Torah tell us that the ark made in the wilderness was covered by a curtain.
Worshipers face the ark when praying because the Torah scroll contained within is the most potent symbol of God's presence in our midst. Indeed, all that is required to make space a synagogue is an ark containing a Torah scroll. To learn more about the synagogue, click here.