KACIO, KECHO, or BAK-THIAN, the largest city of Amun, and the capital of the province of Tonquin, in Asia, situated on the west side of the Toonquin river, about eighty miles from the sea. It is of great extent, and has neither walls nor fortifications, being merely surrounded by a bamboo stockade. The principal streets are wide and airy, and for the most part are paved with bricks and small stones; intermediate spaces being, however, left for the passage of elephants and other beasts of burden. The other streets are narrow and ill paved. Most of the houses are constructed of mud and timber, and thatched with leaves, straw, or reeds, and are generally one story in height. The magazines and warehouses belonging to foreigners are the only edifices built of brick; and these, though plain, yet, by reason of their height and more elegant structure, make a considerable show among the rows of wooden huts. The public edifices are very spacious, but particularly the royal palace, which is several miles in circuit, and is surrounded by high walls. It contains many buildings within its precincts, which are devoted to different purposes, and embellished with a variety of carvings and gildings after the Indian manner, all finely varnished. Besides this palace there are to be seen the ruins of one still more magnificent, which is said to have been six miles in circumference. Cachao is a great commercial resort, and its trade is facilitated by the river, which is always crowded with vessels. The imports are long cloths, chintz, arms, pepper, and other articles, which are exchanged for gold and manufactured goods, namely, beautiful silks and lacquered ware, which last is generally reckoned superior to any in the East. The English factory, which stood on the banks of the river, north of the city, and that of the Dutch, south of it, have long been withdrawn. Cachao, built chiefly of wooden and brick houses, is peculiarly liable to fires; and to prevent these, or to extinguish them after they have broken out, the city is governed by a very rigid police, and is divided into wards, each subjected to a certain jurisdiction. Fires for domestic use are only permitted during certain hours of the day. About the middle of the eighteenth century the city was nearly burnt to the ground by a conflagration, which was the work of incendiaries, who discharged fire-arrows during the night against the straw-covered roofs, and the whole was in a moment in a blaze. Population estimated at about 100,000. Long. 105° 35'. E.; Lat. 21° N.