CHANTABUN or CHANTABURI, the principal town of the Siamese province of the same name, on the east side of the Gulf of Siam, in 102° 6' E., 38' N. It has a small, very mixed population of Annamese, Shans, Burmese and Cambodians and lies about 12m. from the sea on a river which is navigable for boats and has good anchorage for light-draught vessels inside the bar. The trade is chiefly in rubies and sapphires from the mines of the Krat and Pailin districts, pepper, cardamoms and rosewood. In 1905 Chantabun was made the headquarters of a high commis sioner, with jurisdiction extending over the coast districts from the Nam Wen on the east to Cape Liant on the west, which were thus united to form a provincial division (Monton). Chantabun has been since the 17th century, and still is, a stronghold of the Roman Catholic missionaries, and the Christian element amongst the population is greater here than anywhere else in Siam.