La Unión is a municipality in the La Unión department of El Salvador.
It is the capital city of the Department of its same name. It is the largest city in the department also with a population of almost 26,739 inhabitants. On January 16, 2005 the government of El Salvador started building a new port, in order to replace the old one. It will be able to hold more than double the cargo held by the current principal port of El Salvador at Acajutla.
The new port will be finished by November 2008. It will help to increase the growth in this side of the country. One half of the growth is located at the country's capital San Salvador, but a lot of commerce is also transferred to the nearer San Miguel, being also the largest city.