In ecclesiastical architecture, a ciborium is a canopy or covering supported by columns, freestanding in the sanctuary, that stands over and covers the altar in a basilica or other church. It may also be known by the more general term of baldachin, though ciborium is often considered more correct for examples in churches. Really a baldachin should have a textile covering, or at least, as at Saint Peter's in Rome, imitate one. There are exceptions; Bernini's structure in Saint Peter's, Rome is always called the baldachin.
Ciborium of Sant'Ambrogio, Milan; note the rods for curtains. The columns are probably 4th century, the canopy 9th, 10th or 12th century.
The Euphrasian Basilica, Istria, now in Croatia. Columns 6th century and canopy 1277.
Basilica of Saint John Lateran in Rome, by Arnolfo di Cambio
Basilica di San Nicola in Bari
An altar is a table or platform for the presentation of religious offerings, for sacrifices, or for other ritualistic purposes. Altars are found at shrines, temples, churches, and other places of worship. They are used particularly in paganism, Christianity, Buddhism, Hinduism, Judaism, modern paganism, and in certain Islamic communities around Caucasia and Asia Minor. Many historical-medieval faiths also made use of them, including the Roman, Greek, and Norse religions.
Altar in Roskilde Cathedral beneath by a carved reredos
Horned altar at Tel Be'er Sheva, Israel.
Ancient Greek kylix showing a hoplite offering a sacrifice before an altar, around 480 BC. Ancient Agora Museum of Athens in the Stoa of Attalus
The ancient Altar of Pergamon, reconstructed at the Pergamon museum, Berlin.
