Palakkad is the administrative and transport base for visits to Silent Valley National Park, even though the forest entrance is well outside town. Permits and current access rules matter here, so check locally before assuming you can simply turn up at the gate.
The park is the real prize: dense rainforest, lion-tailed macaques, Nilgiri langurs and a very different mood from Kerala's beach-and-backwater circuit. Treat Palakkad as the staging point, not the forest itself.