The Sanctuary, viewed from the Narthex, contains the Altar
The Sanctuary is the the place of the clergy in the Orthodox house of worship .
Traditionally, the Sanctuary is built on the eastern side of the church structure. The church is designed in this manner as we have been taught to pray facing toward Jerusalem. For practical reasons, however, some churches, like ours, are not built in this manner.
Regardless of the direction in which the church faces, the Sanctuary remains a place of great awe. No one may enter the Sanctuary unworthily or without the blessing of the priest, given for a specific task. Just as was the case "in the Old Testament, clergy alone are meant to enter into the Sanctuary, and only after they have spiritually prepared to serve among, and glorify God with, the angels, who are ever present in the Holy of Holies.
We may find ourselves physically occupying different places in the church structure. Nevertheless, it is together, with one voice and in one spirit, that the clergy, the laity, the saints, and the hosts of angels, worship the Lord in His Holy House. These sections are not meant to divide, but to distinguish, each of us, for our unique ministry to our Lord.