- Kaua'i, Westside
Lonely Planet review for Waimea Canyon
Of all Kaua'i's unique wonders, none can touch Waimea Canyon for utter grandeur. While one expects to find tropical beaches and gardens here, few expect a gargantuan chasm of ancient lava rock, 13 miles long and 2500ft deep to the riverbed (or 3700ft above sea level). Flowing through the canyon is the Waimea River, Kaua'i's longest, which is fed by three eastern tributaries that bring reddish-brown waters from the mountaintop bog, Alaka'i Swamp.
From afar, the view of the canyon tends to be hazy. The optimum viewing conditions are sunny days following heavy rain, when the lava layers turn deeper red and waterfalls cascade throughout the canyon.
Waimea Canyon was formed when Kaua'i's original shield volcano, Wai'ale'ale, slumped along an ancient fault line, creating a sharp east-facing line of cliffs. Then another shield volcano, Lihu'e, developed the island's east side, producing new lava flows that ponded against the cliffs. Thus the western canyon walls are taller, thinner and more eroded - a contrast most theatrically apparent while hiking along the canyon floor. The black and red horizontal striations along the canyon walls represent successive volcanic eruptions; the red color indicates that water seeped through the rocks, creating rust from the iron inside.