Sorry that the title is a little bit vague, but let me get into better detail here:

I'm running a campaign, we're about a month in - and so far, all the "dungeons" have been areas that are inherently unplanned and all over the place. A cave system, a dark forest, etc. So I've to do the opposite of intentionally planning out the layout, since I just let a randomizer take care of the layout to make it look and feel natural.

But my players are, in a few sessions, coming up to a dungeon that's a temple for a goddess, now overrun by monsters. How can I make a layout that is like, like an actual temple? I don't like making just a series of rooms to go through, especially because my particular campaign has a big emphasis on exploration. I want an area to be explored that has connected rooms that makes sense, etc.. But I'm having a hard time of knowing where to start, like, architecture wise.