Kolhumadulu Atoll, letter code Thaa is an administrative division of the Maldives. It corresponds to the natural atoll of the same name. The ancient name of the island was Kolhumaduva during the time of King Koimala who united all atolls of the Maldives under one Kingdom for the first time.
NOTE: Haa Alifu, Haa Dhaalu, Shaviyani, Noonu, Raa, Baa, Kaafu, etc. (including Thaa) are code letters assigned to the present administrative divisions of the Maldives. They are not the proper names of the natural atolls that make up these divisions. Some atolls are divided into two administrative divisions while other divisions are made up of two or more natural atolls. The order followed by the code letters is from North to South, beginning with the first letters of the Thaana alphabet used in Dhivehi. These code letters are not accurate from the geographical and cultural point of view. However, they have become popular among tourists and foreigners in the Maldives who find them easier to pronounce than the true atoll names in Dhivehi, (save a few exceptions, like Ari Atoll).