At San Dionisio Village, towards the south of Usulután City, there is a place called "La Iglesia Vieja" (The Old Church). During the colonial era, this place was called "Ucelucla" that in the indigenous language means "Tigers' Place". The Spanish colonizers founded there a town and built a church.

One day, during a Mass, the church sank completely. Some people believe that the church was very near from the sea and the land there was very weak, so that the church sank on its own weight.

People was very scared, so they decided to abandon their homes and moved further north. They founded a new city on the shores of the "Río Chiquito" (Small River), to which they gave the name "Usulután".

According to some villagers, every year on Easter, Wednesday and Saturday , you hear the song of the bells away from the old colonial town.