Other than the exquisite architecture of Siena, Italy, one subconscious reason why people continously gush over its beauty is its lighting.
Notice that with incandescent lighting you can tell that the lady’s coat is actually red. The light fixtures (art pieces unto themselves) are just a few feet above eye level, better illuminating the street. Acting as spotlights, the textures of the buildings are richly illustrated.
Beauty has a price in Siena. The city uses high quality incandescent lighting rather than the yellow wash, but energy efficient high-sodium vapor lighting commonly used in parking lots. Hopefully technology will soon allow energy efficiency without turning this image completely yellow.