Map 4. Rivers and classical states of Southeast Asia: The coincidence of classical states
with navigable water courses is the general rule, as the map illustrates. The Salween/
Nu/Thanlwin River spawned only one classical state, Thaton, at its estuary. For much
of its long course, the Salween runs through deep gorges and is not navigable. It is,
solely for this reason, an exception. Keng Tung and Chiang Mai are also exceptions
in the sense that neither is located close to a major navigable river. Each, however,
commands a large, arable plain suitable for padi cultivation and hence for state-making