Waimoku Falls, East Maui, Hawaii
Located in the Mauka (toward the mountain) area of East Maui, Waimoku Falls has a towering 400 foot drop.
A 2 mile moderately uphill hike along the Pipiwai Trail from the Seven Sacred Pools (Oheo Gulch) will get you to these falls. Be sure to wear appropriate and comfortable footwear for hiking as the trail can be muddy, slippery, and rocky in many parts.
Ideally, you want to arrive in the parking lot at Oheo Gulch no later than 2:30pm because by 4:30pm, some areas of the trail get real dark well before sunset.
Here's a shot of Waimoku Falls back in September 2009 which is well into the dry season.