By far the largest city we visited on the entire trip was Milan, the second most populous city in Italy. Our first stop in Milan was the Santa Maria delle Grazie church, to see Leonardo da Vinci's painting Last Supper, which is on a wall of the church's cenacolo ("supper hall", appropriately enough). The cenacolo is climate-controlled, and entered through a series of small ante-rooms, separated by a set of timed automatic doors, and each slightly cooler than the preceding one. To my surprise, there was another painting on the wall opposite the Last Supper, a Crucifixion of Christ by Giovanni Donato Montorfano. As one can appreciate, photography within the cenacolo is forbidden, so the only evidence I have of my visit is my ticket.
After leaving Santa Maria delle Grazie, we visited the theater known as La Scala ("the staircase"). In an adjacent square was a statue of Leonardo himself.
La Scala includes a large lobby, of which this is a partial view.
We were guided into some of La Scala's many balconies. From the one I was in, I could see the stage and the orchestra pit.
La Scala also includes some museum exhibits, such as these old instruments in a glass case.
This keyboard instrument is a spinet, an ancestor of the modern piano.
Near La Scala (and the statue of Leonardo above) is one entrance to the Galleria Vittorio Emanuele II, which contains shops and restaurants, all underneath a transparent roof.
The central area of the Galleria's floor includes several mosaics, such as this one honoring ancient Rome.
On the side of the Galleria opposite la Scala is a large square that includes this statue of King Vittorio Emanuele II. As you can see, it was pretty crowded.
I'll have the rest of my visit to Milan in Part 2. In the meantime, you can read more about Milan at Understanding Italy, Lonely Planet, About Travel and Wikitravel.