The symbolic center of the church is the altar, because here is where ordinary bread and wine are transubstantiated into Christ's Body and Blood.

In the cathedral, the high altar is directly under a "baldachin" (from the Italian word for balcony). The altar and the baldachin sit on a foundation that is entirely separate from the rest of the Church. This remarkable feat gives a physical form to the ancient concept of building a church around an altar.

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