Mokuiki, also known as Mokulua South, is a massive volcanic cone next to North Mokulea or Mokunui. It is about 875 feet long, 700 feet wide and 150 feet high. Mokuiki has sheer slopes on the northern, eastern, and southern sides of the island.

Most of the plants on Mokuiki go dormant during drought years and adds to erosion. Erosion is a threat especially to nesting sea birds. Their burrows or holes in the dirt collapse and that sufficates the sea birds.