20504 is the Postal Code/ZIP Code for the District of San Isidro in the Costa Rica Province of Alajuela and the Canton of Atenas.
| Postal Code | 20504 |
| Postal Code Name | San Isidro |
| Province | Alajuela Province |
| Canton | Atenas Canton |
| Timezone | Central Standard Time (CST) |
| Adjacent Postal Codes | 20206 20402 20502 20503 20506 20704 20705 |