Getting Here and Around
Zamoskvoreche is served by the Tretyakovskaya, Polyanka, and Oktyabrskaya metro stations. It's better to take the metro or other transportation to this neighborhood, as opposed to walking, because the only way across the Moskva River at most points is over a large, traffic-filled bridge. The main exception to this is the pleasant pedestrian bridge on one side of the Cathedral of Christ Our Savior. Once in the neighborhood, it's most efficient to walk between sights, though you should give yourself plenty of time for doing so, as Zamoskvoreche covers a large area.
There’s a lot to see in this area so it might be worth spending a day or even two on the sights. To truly enjoy the Tretyakov Gallery, it's probably best to plan a separate visit. A full exploration of Gorky Park could also easily take an afternoon. Note that many of the sights are closed on Monday.