see-AIR-uh lee-OHN
* see-AIR-uh: The "Sierra" part is pronounced with a long "e" sound, similar to the word "here."
* lee-OHN: The "Leone" part is pronounced with a long "e" sound, similar to the word "alone."
The "e" in Sierra and Leone should be pronounced with a long sound, not a short "eh" sound.