River erosion caused by heavy rain in the interior of the island have carved deep valleys that now form Waimea Canyon. From one of the many over-looks, we can see here the many different layers of rock exposed in the canyon walls. Unlike the Grand Canyon in Arizona, the rocks of Waimea Canyon are entirely volcanic -- indeed, this is a great place to look into the "inside" of a Hawaiian volcano.
By happenstance, the old volcano of Kauai had a summit caldera that was full when the volcano ceased erupting. This meant that the lava flows filling the caldera formed dense thick layers of rock that are more resistant to erosion than the flanks, so that they have eroded away more slowly. A high plateau (seen in profile here) in the interior of the island, which now forms Alaka'i Swamp, is now the result.
From here you can continue on to Stop 3 on the ground, or you can pick another point from the Kauai Virtual Field Trip page.