Puerto de Cutuco is La Unión's modern port complex, built to handle larger shipping on the Gulf of Fonseca. It is not a tourist sight in the usual sense, but it explains the town: La Unión has always looked outward to the gulf, trade, and border waters.
You will see more from the roads and waterfront than from inside the port, where access is restricted. It is worth noting if you are interested in the economic geography of eastern El Salvador, or if you want to understand why this small city has a more strategic feel than its size suggests.