Hm. That’s a rather awkward visual. I’m also not sure if the building is two stories high, if the crystals are two stories high, if the crystals are supporting the building off the ground, or if it’s the crystals or building creating the light.
Now, Greco-Roman architecture is not all that hard to describe. In general, the buildings would have columns in front, stairs leading up to the doorway, which could be wide and open or with a stout wooden door, depending on the usage, and a peaked roof. I’d drag out all the proper terms for each component, but anyone can Google that. The point is that it’s not hard to describe a structure if you approach it logically:
“After a short trek in the ankle high water, Loric found what looked to be some kind of temple ruins. Blue crystalline columns supported the structure, rising at least three meters out of the water, and their radiance illuminated the pale stone of the temple. The remnants of a broad stair, flanked by tall columns capped with intricate carvings, led up to an intimidatingly dark opening beneath the crumbling pediment.”
Or something to that effect…