Some of the most beautiful buildings are those that can harness natural light and bring it inside, giving the illusion of being outdoors. Churches in particular are good at this, often being tall buildings with lots of windows. La Sagrada Familia in Barcelona makes you feel as if you are walking in a forest, with the light filtering down through the trees.
St. Peter’s Basilica in the Vatican, though done in a completely different style, is also amazing in this respect. The windows up high in the famous dome let heavenly rays of light come shining down.
Of course, natural light is part of what makes landscapes so compelling. In Ireland, the light is always changing as the clouds move, sometimes intense and sometimes soft. It’s part of what makes the “forty shades of green!”