Fiestas de la Calle San Sebastian in Old San Juan
Known locally as La SanSe, the San Sebastian Street Festival takes over Old San Juan on the third weekend of January, marking the unofficial end of Puerto Rico's long Christmas season. Revived in 1970 from a small 1950s parish procession, it now draws crowds of well over 200,000 with music, crafts and the iconic Cabezudos parade.
For four days every January, the narrow colonial streets of Old San Juan fill to a scale that dwarfs the neighborhood's everyday population, as hundreds of thousands of people arrive for what locals simply call La SanSe, the San Sebastian Street Festival.