Pyramids are structures, triangular in shape with a square base and usually made from stone. They appear to have been first created by the Goa'uld due to their use of the Ha'tak class ships. It is possible that they used the local population as slave labor to build these structures.
The main function of a pyramid is that it is used as a landing site for the Goa'uld Ha'taks. Due to this, most pyramids were built with Transportation rings to allow transport between the planet and the ship. (Stargate) (SG1: "Double Jeopardy", "Off the Grid")
Pyramids on EarthEdit
When Dr. Daniel Jackson first proposed that the pyramids were alien landing pads, many people believed it to be simply a radical theory with no truth. As a result he was ostracized from the scientific community. His theory was later proven right when he saw a pyramid used for his suggested purpose on the planet Abydos for the first time after traveling through the Stargate. (Stargate)