The World Heritage Committee of the United Nations Educational, Scientific and Cultural Organization decided to add the two sites on Friday as it held a 10-day meeting to revise the list in Brasilia.
The additions brought to 892 the number of environmentally or culturally unique sites considered important to our planet and civilizations.
Sri Lanka's highland region, situated in the south central part of the island, was added because of its "extraordinary range of flora and fauna," which includes endangered species such as the langur and loris primates and the Sri Lankan leopard, a UNESCO statement said.
The United States' Papahanaumokuakea archipelago, located 250 kilometers (160 miles) northwest of the main group of Hawaiian islands, was included because of its "deep cosmological and traditional significance for living Native Hawaiian culture... as the place where it is believed that life originates and to where the spirits return after death."
During its meeting in the Brazilia