There was a fiesta yesterday - I asked someone what what was going on, but she didn't know. The closest Catholic holiday per Wikipedia is the Ascension (May 17 this year)...
The festivities were down by the church and soccer field, and were announced periodically by the town cannon / fireworks-engine (two booms followed by explosions in the sky). There were several soccer games throughout the day, horses galore, horse-riding contests, a raffle, vendors, and a priest using greenery (I don't know what kind, or if there was any significance to the kind) to shower the crowd with water.
The horse riders seemed to enjoy putting little kids up on their horses and walking them around - Mariela's Joel (~4 years old) got to do this. Boy, was he happy!
Later that evening, everyone disappeared into houses and bars to watch the Costa Rican soccer finals - the Saprissas won! What a game! When the end of the game was announced you could hear people spilling into the streets, shouting, laughing, and honking horns. The will be going on to the international games, so look for purple and white (with a splash of orange) on your TVs soon.