Short answers, pulled from the story.
The word altar derives from the Latin altare, probably connected to adolere, meaning to burn, and influenced by altus, meaning high. It entered English through Middle English altar and Old English alter, displacing the native Old English word wēofod.
The Ara Pacis is one of the most important surviving Roman altars, dedicated by Augustus Caesar at the beginning of the Pax Romana to the goddess of peace, Pax. It is significant both as a religious monument and as a political statement in stone from the Augustan era.
The word altar, in Greek thysiasterion, appears twenty-four times in the New Testament. Its repeated use reflects the central role of the sacrificial concept in early Christian theology.
An antimension is a silken cloth imprinted with an icon of Christ being prepared for burial, with a relic sewn into it and the signature of the bishop. The Divine Liturgy must be served on an antimension even when the altar itself has been consecrated and contains relics.
A carroccio was a four-wheeled mobile shrine used by medieval Italian city-states, pulled by oxen and equipped with a flagpole and a bell. Mass was celebrated on it before battle, and it simultaneously served as the army standard.
High places, called bamah in Hebrew, were open-air shrines erected on elevated sites. Before the Israelite conquest of Canaan in the twelfth to eleventh century BCE they served as shrines of the Canaanite fertility deities, the Baals and the Asherot. They included altars and stone pillars called matzevot representing the divine presence.