Kailua is a census-designated place (CDP) in Honolulu County, Hawaii, United States. It lies in theKo?olaupoko District of the island of O?ahu on the windward coast at Kailua Bay. It is in the judicial district and the ahupua'a named Ko'olaupoko. It is 12 miles (19 km) northeast of Honolulu – over Nu‘uanu Pali. The population was 38,635 at the 2010 census.Kailua Beach is crescent-shaped, about 2.5 miles (4.0 km) long, and ranging between 50 and 150 feet (15 and 46 m) wide. The ocean bottom fronting the beach slopes gently to overhead depths without any coral heads. Light to medium waves support surfing and bodysurfing. The steady trade winds make Kailua Beach a top windsurfing and kitesurfing destination. Robby Naish, first World Champion of windsurfing and Professional Windsurfers Association Hall of Fame inductee, grew up in Kailua.During the reign of King Kakuhihewa and his successors, Kanekapu, Kahoowaha, Kauakahiakahoowaha, andKualii, Kailua replaced Waikiki as the residential seat of the Alii Aimoku of Oahu. Many ancient temple ruins, such as those at Ulupo Heiau State Historic Site, are in the area.