oahu things to do

Kawainui Marsh and Ulupo Heiau

Kawainui Marsh is Hawaii’s largest remaining wetland encompassing 830 acres. Kawainui receives the waters from rains in the uplands of Maunawili Valley. A traditional fishpond in ancient times, Kawainui was planted with rice during the 1900s. Today Kawainui has been restored as a wetland that provides valuable habitat for Hawaii’s native waterbirds including the stilt (aeo), coot (alae keokeo), duck (koloa) and moorhen (alae ula). At least 60 species of birds, fish, and other aquatic life thrive at Kawainui.

Kawainui Marsh Trail, Oahu, Hawaii by 4K Relaxation Channel

Kawainui means “The big water,” which is a fitting name since it was Hawaii’s largest cultivated inland fishpond in ancient times. Numerous cultural and archeological sites are found throughout the area including heiau (sacred sites). Overlooking Kawainui Marsh is Ulopo Heiau comprised of stones that extend for a length of about 180 feet and up to 30 feet high. Ulopo means “night inspiration” and it is believed that the site was used as a luakini heiau where human sacrifices occurred.

Kawainui Marsh
Kawainui Marsh is Hawaii’s largest remaining wetland encompassing 830 acres


From Waikiki take the H-3 east to the windward side. Turn right on Mokapu Saddle Road, then turn right on Oneawa Street, then right on Kaha Street to the Kawainui Neighborhood Park. To get to Ulupo Heiau from Honolulu take the Pali Highway to Uloa Street, which is the first left turn after the Hwy. 72 junction. Turn right on Manu Aloha Street, and then right on Manuoo Street. Ulupo Heiau is located behind the YMCA.