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.
The modern English word altar was derived from Middle English altar, from Old English alter, taken from Latin altare ("altar"), probably related to adolere ("burn"); thus "burning place", influenced by altus ("high"). It displaced the native Old English word wēofod.
File:Tel Be'er Sheva Altar 2007041.JPG|Horned altar at [[Tel Be'er Sheva]], [[Israel]].
File:3217 - Athens - Sto... of Attalus Museum - Kylix - Photo by Giovanni Dall'Orto, Nov 9 2009.jpg|[[Ancient Greece|Ancient Greek]] [[Kylix (drinking cup)|kylix]] showing a [[hoplite]] offering a sacrifice before an altar, around 480 BC. Ancient Agora Museum of Athens in the [[Stoa of Attalus]]
File:Berlin - Pergamonmuseum - Altar 02.jpg|The ancient [[Pergamon Altar|Altar of Pergamon]], reconstructed at the Pergamon museum, Berlin.
File:Opferstein Maria Taferl.jpg|The ''Opferstein'' or Sacrifice Rock at [[Maria Taferl]], [[Austria]]. It was used by the ancient [[Celts]] to make sacrifices upon and is now located in the plaza of the [[basilica]] there.
Altar (Bible)
Altars in the Hebrew Bible were typically made of earth or unwrought stone. Altars were generally erected in conspicuous places. The first altar recorded in the Hebrew Bible is that erected by Noah. Altars were erected by Abraham, by Isaac, by Jacob, and by Moses.
After the theophany on Mount Sinai, in the Tabernacle—and afterwards in the Temple—only two altars were used: The Altar of Burnt Offering, and the Altar of Incense, both near where the Ark of the Covenant was located.