ʻŌpaekaʻa Falls is a waterfall located on the ʻŌpaekaʻa Stream in Wailua River State Park on the eastern side of the Hawaiian island of Kauai. It is a 151–foot waterfall that flows over basalt from volcanic eruptions millions of years ago. Below the ridge down into the ravine through which the water falls can be seen the vertical dikes of basalt that cut through the horizontal Koloa lava flows. The name "ʻŌpaekaʻa" means rolling shrimp, "ʻopae" being Hawaiian for "shrimp," and "kaʻa" for "rolling". The name dates back to days when the native freshwater shrimp Atyoida bisulcata were plentiful in the stream and were seen rolling and tumbling down the falls and into the churning waters at the fall's base.