Lake Merritt is a great running opportunity right near downtown Oakland. A 3.2 mile path goes around the circumference of the lake. One can start anywhere, but Grand Ave. provides good access. The Oakland Museum of California is located at the south side of the park, while Lakeside Park, which includes a lovely Bonsai Garden, is at the north side of the park. You’ll also run by the Cathedral of Christ the Light.
For a little extra and some hill work, run up the Cleveland Cascade, a set of stairs that connects Lake Merritt with the hill neighborhoods. It’s like running up three stories.