Parque Libertad anchors the historic center and is a good place to start a visit. The combination of the cathedral, the teatro, and the older civic buildings around the square creates a coherent architectural ensemble that gives Santa Ana a dignity uncommon in Central American secondary cities.
Sit on a bench in the late afternoon to see the square at its most active — vendors selling pupusas and fruit, children from the nearby schools, and office workers cutting through on their way home. It costs nothing, and it's a better introduction to the city than any museum.