Nano Banana was the first generative image tool that seemed to understand architecture. I have some 18th century engravings that I've been trying to get AI tools to visualize as though they were photographs of real structures, and the results were comically bad until Nano Banana came along. I remember seeing the announcement, dropping a sketch into Gemini with the prompt "Make this a photo" and it preserved all the features and dimensions, but added photorealistic textures.

I still do a lot of modeling of historical buildings in Sketchup and Twinmotion, but Nano Banana has really helped me with more easily visualizing a world before photography.