The famous bamboo grove path is crammed 10 AM – 4 PM. Go at 6 AM for golden light and no crowds.
The grove itself takes only 10 minutes to walk. Combine with Tenryu-ji temple, Okochi-Sanso villa, and a stroll along the Hozu River.
Monkey Park Iwatayama (across the river) is a fun 30-minute hike — wild macaques you can feed from a cage (you're inside, they're outside).