A Stargate is sealed underneath, you might also notice some interesting symbols written inside the Cartouche
This is what you'll see once you break the seal, better known as the Alpha gate to those who know Stargate SG-1 well (Also yes, Stargates can be placed facing both up and down)
Earth's original Stargate, better known as the Beta gate to those who know Stargate SG-1 well
The Abydos Pyramid and the three moons of Abydos: Edfu, Dja'Net and Nuturo
Jaffa Armor - Jackal Guard
A version of the Goa'uld Temple found on Abydos
Chulak Stargate Pedestal
Planet orbiting a black hole
Night on Lantea with Stellar View installed
The Pegasus Stargate on Lantea
The Movie Variant of the Milky Way Stargate, placed in the Abydos Pyramid's gateroom
Universe Stargate
Tollan Stargate
This is how you set the blocks to build a Classic Stargate
Classic Stargate, based on the Stargate model in SG Craft
Stargates can have many different Symbols depending on where they come from