Nam bo, formerly known as Nam Ky, represents an area of 56 000 km2. It is the result of filling the Gulf Quaternary era, concomitant with the emergence of a shallow submarine base. This filling which is continuous, is the work of a great river, the Mekong delta which irrigates 50,000 km2, of which 40 000 km2 in Vietnam. North and east of the country, totaled only mountainous regions (one should rather speak of hills, since the peaks do not reach 1,000 m). The coastline is decidedly flat, with the most notable exception, Cape Saint Jacques ( Vung Tau today ) and 500 m. Along the coast are divided many beautiful resorts, not to mention the famous Halong Bay with its 3 000 reefs , reconue by UNESCO as World Natural Heritage. Vietnam has many forests in yet exploited, fauna and flora ganda value, high temperate climate regions very taken by tourists and countless lakes, rivers, streams, waterfalls and caves.