The Underwater Ruin is a ruin of an ancient civilization sunken deep beneath Moga Island. The Elder Dragon, Ceadeus, makes its home here along with Goldbeard Ceadeus and the Abyssal Lagiacrus. There is a shortcut from base camp to Areas 2 and 3 available when you have repelled Ceadeus. The battle soundtrack of Underwater Ruin is the same as the Tower's battle soundtrack. A Dragonator and two ballistae are found in these ruins,supposedly built by the old ancestors of the Moga Village Chief to keep monsters, like Ceadeus, at bay.