Lyon Arboretum has over seven miles of hiking trails and boasts more than 6,000 taxa of tropical and sub-tropical plants on nearly 200 acres.  One of the main trails leads to Aihualama Falls. That hike is approximately 1.2 miles out & back with a 357 foot elevation.  Not a hard hike but it was muddy in a lot of places. There were so many trails that i just wondered around trying most of them.