It’s 1750. Kailua is the political seat of power for the district of Ko’olaupoko and a favored place of the O’ahu chiefs for its abundance of fish and good canoe landings. The houses of the ali’i (chiefs), their families, and their attendants surround Kailua Bay. Behind the sand beach is the large, fertile expanse of Kawai Nui which has been converted to a fishpond surrounded by an agricultural fieldsystem. Kawai Nui is a large, 400 acre fishpond with an abundance of mullet, awa, and o’opu. Ka’elepulu and Nu’upia fishponds are nearby. The maka’ainana (commoners) provide support for this chiefly residence. Farmers grow kalo (taro) in the irrigated lo’i (fields) along the streams from Maunawili and along the edges of the fishponds. Crops of dryland kalo, banana, sweet potato, and sugarcane mark the fringes of the marsh. The fishermen harvest fish from the fishponds and the sea. The kahuna (priests) oversee the religious ceremonies and rites at several heiau around Kawai Nui. There is Ulupo Heiau on the east with Pahukini Heiau and Holomakani Heiau on the west side.
Hauwahine, the mo’o or guardian spirit, protects the people of Kawai Nui and assures an abundance of fish. The legendary association of Ulupo Heiau with the menehune suggests the antiquity of this site. The massiveness and quantity of rock carried many miles hint at its cultural importance. Tradition records Kualoa, more than 10 miles away, as one source of these stones.
It is likely that the function of this heiau changed over time. It probably began as a mapele or agricultural heiau with ceremonies and rites conducted to insure the fertility of the crops grown in Kawai Nui. In later times, it may have become a heiau luakini dedicated to success in war with structures erected atop this massive stone platform, including an altar, an oracle tower or anu’u, thatched hale, and notches in the terraces to hold the ki’i or wooden images. The spring off the corner of the heiau was another important feature related to the ceremonial traditions of the site.
Ulupo Heiau measures 140 by 180 feet with walls up to 30 feet in height. The construction of this massive terraced platform required a large work force under the direction of a powerful ali’i. Several O’ahu chiefs lived at Kailua and probably participated in ceremonies at Ulupo Heiau, including Kakuhihewa in the 1400s and Kuali’i in the late 1600s. Kuali’i fought many battles and he may have rededicated Ulupo Heiau as a heiau luakini. Maui chief Kahekili came to O’ahu in the 1780s and lived in Kailua after defeating O’ahu high chief Kahahana for control of the island. Kamehameha I worked at Kawai Nui fishpond and is said to have eaten the edible mud (lepo ai ia) of Kawai Nui when there was a shortage of kalo. But by 1795 when Kamehameha I conquered O’ahu, it is believed that Ulupo Heiau was already abandoned.
–Hawai’i Department of Land & Natural Resources