In Genesis, Noah built an altar before offering sacrifices after leaving the Ark.
Genesis 8:20 says Noah built an altar to the Lord after the waters had receded and he, his family, and the animals had left the Ark. He then took some clean animals and clean birds and offered burnt offerings. The passage presents this as Noah’s first recorded act after the Flood.
The altar should not be confused with the Ark itself or with a later temple. Genesis does not say Noah built a permanent sanctuary at that moment. The episode also occurs before the covenant sign of the rainbow in Genesis 9, linking worship, the end of the Flood, and the divine promise not to destroy the earth with a flood again.