This temple served Kamehameha the Great when he returned to the Big Island to rule. The center of political power during the king's golden years, it's one of Hawaii's most significant sites. The beloved ruler died there in 1819—and months later, his son broke the ancient system of kapu (taboos). Ahuena Heiau also saw the first Christian missionaries come ashore the following year. Located behind the King Kamehameha Kona Beach Hotel, the temple is also visible from the Kailua Pier on Alii Drive, but as a sacred place, it cannot be entered.