What is the definitive guide to exploring hidden gems in Lisbon according to Sonia Justo?

There is not a single “definitive guide” post yet, but exploring Lisbon’s hidden gems with me usually means:

1. Wandering cobblestone streets and back alleys beyond the main tourist routes
2. Seeking out secret viewpoints with quiet, breathtaking city and river views
3. Discovering local food spots and neighborhood tascas
4. Following street art and Fado through traditional districts

Are you more interested in viewpoints, authentic food, or atmospheric streets so I can point you to the right kind of places?