The ancient Buddhist stupas are called "havitta", "hatteli" or "ustubu" by the Maldivians according to the different atolls. These stupas and other archaeological remains, like foundations of Buddhist buildings Vihara, compound walls and stone baths, are found on many islands of the Maldives. They usually lie buried under mounds of sand and covered by vegetation. Local historian Hassan Ahmed Maniku counted as many as 59 islands with Buddhist archaeological sites in a provisional list he published in 1990. The largest monuments of the Buddhist era are in the islands fringing the eastern side of Haddhunmathi Atoll.