The lower part consists of some parks and gardens. They are technically separate and have names of their own, but in practical terms it's just one big area of parkland. The south side of the avenue is a bit more “wild” (that is, less formally landscaped) than the north side. In among the trees and gardens, there are two well-known theaters (Théâtre du Rond-Point and Théâtre Marigny), several fancy restaurants, some conference venues, snack bars, two huge 19th-century exhibition halls (the Grand and Petit Palais), scattered statues, two sanisettes, two Wallace fountains, a gazebo, and other things. All of this is shown in my video.
The south and lower portion of the Champs is the quietest part of the avenue. There are some scattered benches among the trees, and it's fairly peaceful despite the close proximity of so much traffic. The north side is nice, too: there are more people, but the area is much more carefully landscaped. It's surprising how quickly the traffic fades as you move into the park areas.
On the south side of the south side, so to speak, there's a street called Cours La Reine, which is a major, official parking area for tour buses. This street is usually packed with such buses. It's the closest official parking place to the Champs itself.
The Grand Palais is huge, and is designed with a minimum of internal supporting columns and a glass roof. It's a great spot for large exhibitions, and was intended for them. The Petit Palais is smaller, as the name implies, but is also intended for and well suited to exhibitions. Part of the Grand Palais is permanently dedicated to the Palais de la découverte, a science museum with a lot of interesting, hands-on exhibits.
Anyway, this video is done and online. Next up will be (I think) Les Halles.