La Unión is El Salvador's eastern port, set on the Gulf of Fonseca where El Salvador faces Honduras and Nicaragua across sheltered Pacific water. It is hot, workaday, and far from the country's usual tourist circuit. That distance is part of the draw: the landscape opens into mangroves, islands, naval docks, and the dark cone of Volcán Conchagua.
Most travellers come through La Unión for boats into the Gulf of Fonseca. Isla Zacatillo and Isla Meanguera are the most realistic island targets, with fishing villages, simple seafood, and views back toward the mainland volcanoes. This is not resort territory; arrangements are local and weather-dependent.
The best land excursion is up Conchagua, where the miradores look over the gulf's islands and across two international borders. If you have your own transport or a good local driver, La Unión becomes a rewarding base for a part of El Salvador that feels almost separate from the coffee highlands and surf coast.