Any raised structure used to offer sacrifices to a god was an altar. Abraham, Isaac, and Jacob each made or restored altars to God after defining moments in their lives. During Israel’s journey through the wilderness, the Tabernacle (God’s portable Temple) had two altars: one for burnt offerings, made of wood and bronze, and another for incense, made of wood and gold. Altars were also used to remind future generations of a particular event, like the one erected by Joshua as a monument to the tribes east of the Jordan to symbolize their unity with the rest of Israel. The altar in Jerusalem’s Temple was originally built by Solomon, but was rebuilt and rededicated many times throughout Israel’s history. However, altars weren’t unique to Israel’s religion – many ancient cultures used them to offer sacrifices to their gods. In fact, Paul records that Athens had so many altars that one was dedicated to an “unknown god” to make sure no deity was missed.