There are two main divisions, the Lao Pong Dam ("Black Paunch Laos"), so-called from their habit of tattooing the body from the waist to the knees, and the Lao Pong Kao ("White Paunch Laos") who do not tattoo.
The Lao Pong Kao, or eastern branch, appear to have migrated southwards by the more easterly route of the Nam-u and the Mekong valley.
Some of the islands are built of volcanic rocks alone; such are Hongu-tonga and Hongu-hapai, which appear to be fragments of a single ancient crater, Tofua, Kao, Late, Metis, Amargua and Falcon Island.
The highest mountain is Kao Luang, an almost isolated projection over 5000 ft.
The Annals of the North, the Annals of Krung Kao (Ayuthia) and the Book of the Lives of the Four Kings (of the present dynasty) together form the only more or less connected history of the country from remote times down to the beginning of the present reign, and these, at least so far as the earlier parts are concerned, contain much that is inaccurate and a good deal which is altogether untrue.