The district was established in December 1901. It comprises of these 4 island groups : Mu Ko Lanta (170 km²), Mu Ko Klang(162 km²), Mu Ko Rok(3.5 km²) and Mu Ko Ngai(3.6 km²). Some more island groups are smaller, like Mu Ko Haa. The origin of the name is unclear, but it may originate from the Javanese word lantas, meaning a type of grill for fish. The name of the island was officially changed to "Ko Lanta" in 1917.
From archaeological discoveries, it is believed that the area was one of the oldest communities in Thailand dating back to the prehistoric period. It is believed that this province may have taken its name after the meaning of Krabi, which means sword. This may have stemmed from a legend that an ancient sword was unearthed prior to the city’s founding.p[Source]