Does anyone know why Costa Rican cities are so modern, compared to other Latin American countries?

I think this is the only Latin American country whose cities have no "Old Town". It just seems to be a couple of heavily restored "historic" buildings here and there, but the rest is all ugly buildings used for commercial purposes. There's no forts even. What gives? Why is there no Old World Charm in Costa Rica?
Downtown San Jose
Downtown San Jose
San Jose Plaza and Cathedral
San Jose Plaza and Cathedral
Downtown Heredia
Downtown Heredia
Liberias Most Famous Landmark
Liberia's Most Famous Landmark
Downtown Limon
Downtown Limon
Does anyone know why Costa Rican cities are so modern, compared to other Latin American countries?
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