Easily accessed near the northern outskirts of Hilo on the Big Island of Hawaii, Rainbow Falls is a beautifully dynamic waterfall on the Wailuku River. The falls get their name from the colorful rainbows that can often be seen in the mist that rises from the circular collecting pool 80 feet below.
The area that contains the falls is often referred to as Rainbow Falls State Park, although it is technically part of Wailuku River State Park, which starts a couple of miles upstream from here. The Hawaiian name for the waterfall is Waianuenue, which quite literally means "rainbow seen in water.''
Wailuku River State Park consists of 16.3 acres of protected land along the 18-mile-long Wailuku River, which is the longest river in Hawaii. Its name means "waters of destruction,'' and after a heavy rainfall, its current can indeed be a raging flood. At such times the rushing torrent that streams over Rainbow Falls looks like a muddy version of Niagara.
Most of the time, however, the water pouring from the lip of Rainbow Falls is a steady flow and exceedingly clean. One of the best times for catching a glimpse of the rainbow effect is early morning, and especially just after dawn, when the rays of the sun are angled just perfectly for refracting through the filtering mist. Another good time for viewing is when the sun comes out immediately after a good rain. That's when the volume of water increases and so does the amount of mist it creates.
Directly behind the waterfall is a huge natural cave, carved into the rocky cliff by centuries of powerful splash back. According to ancient legends, this was the home of Hina, mother of the demigod Maui. The roar of the falling water could well be her throaty singing.
The vegetation around the basin of the falls is lush and typical of the local rainforest. It includes mango trees covered with philodendron, African tulip trees, kukui (candlenut - the Hawaiian state tree), banana trees and a variety of tropical flowers.
There is no access to the river, the falls or the collecting pool from the park entrance, so visitors should not plan on swimming here. The only facilities are the scenic lookout with its protective railing, the paved parking lot, and simple restrooms.
While in the area, visitors are well advised to follow Waianuenue Avenue upstream to the end of Pe'epe'e Falls Drive. That's where the Wailuku River's current forms a number of cascading pools that roll and swirl after upslope rains - a region known as the Boiling Pots. From the overlook there, Pe'epe'e Falls can be seen, too.
Rainbow Falls are located at Rainbow Drive, Hilo 96720. To get there from town, just drive up Waianuenue Avenue about two miles and bear to the right on Rainbow Drive. The Rainbow Junction Gift Shop can be seen across the road from the park entrance. The parking lot will be on your right, and the lookout is just 50 feet beyond. Admission is free and the park is open every day of the year from sunrise to sunset.