is it possible to add a building to a moon?
lets say a great pyramid on an uncolonized moon
and when you explore it it be there?
lets say a great pyramid on an uncolonized moon
and when you explore it it be there?
I'll need more information to be certain, but probably yes. Can you provide more context as to when you want the building to appear? I'm guessing you don't want it to appear on every habitable planet and moon you survey, but instead on a specific one. I'm also assuming you are referring to habitable worlds. Uninhabitable worlds have hidden tiles so the answer in that case would be no.
There could be several ways of doing this. If you want there to be a system somewhere out there in the galaxy that has this special feature, you could make a special system initializer and tell the game to put the building on one of the moons in that system. Then when you (or someone else) surveys that system, the building will appear on the planet's surface. Haven't tested this so can't be sure, but should work.
Another method might be to just create a new anomaly category and anomaly event and set the appropriate limits. This would result in the pyramid not appearing until the anomaly is researched (I think), but would allow you to create a whole storyline to go with the pyramid. This might work better than the system initializer.
Personally, I would create the anomaly rather than creating a new system initializer. Much simpler and also gives you more options.