port, south-central Thailand. It lies on the northern Gulf of Thailand coast, at the head of a small bay protected by Phra Island. It was developed as a naval base in 1920–23 and continued to serve predominantly military purposes in the 1970s. It is linked to Bangkok by river and by a coastal road, and its deepwater facilities are regarded as a potential commercial alternative to Bangkok's shallower port. Pop. (1980) urban sanitary district, 13,812.