If you’re renting a car in Kauai, make certain to check out the tree tunnel, a canopy of Eucalyptus trees lining Maliuhi Road (near Koloa). We couldn’t find a good (i.e. not dangerous) place to stop to take photos. These were taken through the windshield.
There was a bit of a rainbow at Wailua Falls when we visited. That made the sight even more special!
Wailua Falls can be viewed from the road. No hiking is required. This beautiful double waterfalls was featured in the opening credits of Fantasy Island.