The Jewel Lake loop has just one gently descending set of steps, leading toward a view point of the lake.
Keep a close watch of the scrub, where you'll see a variety of birds, some native, some migrating -- depending on the time of year.
Species I've seen around Jewel Lake include: Towhees, bluejays, juncos, swallows, robins and warblers.
If you go near dusk, you may be lucky (or unfortunate, depending on your perspective) to see a few bats flit around the lake. For me, it's luck. I happen to love bats.