Yaku Water Museum sits above Quito's historic centre on the slopes of El Placer, with views that are almost reason enough to climb up. Inside, the museum turns water into the subject: where it comes from, how the city uses it, and why Andean ecosystems matter to life below.
It is especially good with children, but adults who enjoy urban ecology will get something from it too. Combine it with San Juan or the western edge of the old town, and allow time for the terraces rather than treating it as a quick indoor exhibit.