They built the altar of burnt offering of acacia wood, three cubits high; it was square, five cubits long and five cubits wide. They made a horn at each of the four corners, so that the horns and the altar were of one piece, and they overlaid the altar with bronze.
The first seven chapters of Leviticus details a variety of offerings which were made on the altar in the Tabernacle. These included
* Burnt Offerings
* Grain Offerings
* Fellowship Offerings
* Sin Offerings
* Guilt Offerings
For Sin and Guilt offerings, worshipers placed their hands on the head of the sacrificial animal to symbolize their sin being transferred to the offering. The fire of the altar was from God and therefore Holy. His Holy fire consumed the sins/guilt of the worshiper when the sacrificial animal was placed on the altar.
In this same way Jesus is the sacrificial lamb which we transfer our sin onto and the cross is the altar which redeems us of that sin.
At the Tabernacle Experience they had pieces of wood to take up to the altar and throw onto the fire to symbolize us throwing our sins/guilt on the altar of the Lord. This is the part that made the greatest impression on my daugther. She told anyone who would listen about it the next day.