Huilua Fishpond , Ahupua ‘ s O Kahana State Park on Windward O’ahu , is one of the few surviving ancient Hawaiian fishponds that were still operating well into the 20th century.  It was declared a US National Historic Landmark in 1962, shortly after it was severely damaged by the 1960 tsunami .  It was added to the National Register of Historic Places on L: December 29, 1962. 
The fishpond may have started as a sandbar where the ocean currents puts the stream mouth. A 500-foot (150 m) permeable rock seawall (called kuapā in Hawaiian ) was added along the shoreline to enclose about 7 acres (28,000 m 2 ) of fertile brackish water . The wall was about 4 feet (1.2 m) wide and stood about 4 feet (1.2 m) above high tide, with two lashed-pole gates (called mākāhā ) The name Huilua, which can be translated ‘join-twice’, may refer to the two gates. The favorite type of fish in the pond were ‘ ama ‘ ama ( mullet), which reproduce in the ocean but can live in fresh, brackish, or salt water. 
Many Hawaiian fishponds were built about 400 to 600 years ago. They were especially numerous in large expanses of shallow sea, such as Kāne’ohe Bay and Pearl Harbor . Each fishpond had a pondkeeper ( kia ‘ i loko ) who lived nearby and oversaw its maintenance. Sam Pua Ha ‘ aheo was the pondkeeper for Huilua from 1924, just after the 1923 tsunami, until 1946, when another tsunami hit. The fishpond suffered further tsunami damage in 1957 and 1960 . The most recent restoration work began in 1993 as a cooperative project between the State Park Service and Friends of Kahana, an organization of local residents.
- ^ Jump up to:a b National Park Service (2007-01-23). “National Register Information System” . National Register of Historic Places . National Park Service.
- Jump up^ “Huilua Fishpond” . National Historic Landmark summary listing . National Park Service. Archived from the original on 2007-03-01 . Retrieved 2008-06-21 .
- Jump up^ “Ahupua’a ‘o Kahana State Park” (PDF) . State of Hawaii, DLNR. Archived from the original (PDF) on 25 September 2010 . Retrieved 25 March 2012 .
- ^ Jump up to:a b c “State of Hawai’i: Huilua Fishpond” (PDF) . Archived from the original (PDF) on 2010-09-25 . Retrieved 2010-01-03