Here is a concept of SpaceX's early
Mars Base Alpha by Twitter user
Sotiris. The concept features a pair of crew
Starships with
Falcon 9 style landing legs, several pressurized Mars Cybertrucks,
The Boring Company's tunnel boring machine and 3-level
habitation modules derived from used Starship propellant tanks and connected in pairs (a questionable idea, we think).
Cutaway of the habitation module: