Many important historical areas exist along the Royal Coconut Coast. The most heavily concentrated historical areas lie along the Wailua River. This sacred land offered a strategic advantage for the ancient Hawaiians who inhabited the area. The Wailua River is fed from the constant rainfall that occurs at Mount Waialeale, one of the rainiest places in the world. The constant supply of water made the land along the river very sacred, as the ancients never feared a drought or food shortage. This land was once reserved only for the alii or royalty of Hawaii. Many sacred sites, including heiau, or places of worship, still exist along the river. These sacred sites were areas where important cultural customs and traditions, ceremonies, and worship and religious practices were performed.