It is a 3rd class municipality in the province of Sorsogon, Philippines.

According to the 2007 Philippine census, it has a population of 49,407 inhabitants.

Majority of the males (62.02%) falling under working age population were employed while only a little over 10% of the females were employed. Out of the municipality’s labor force, majority (52.54%) were not economically active who were either too old, sick, or still at school age. Overall, the total employment rate in Castilla was only 40.95% while unemployment was recorded at 6.50%. This is expected considering that there is inadequate employment opportunity in the municipality.

 

Source:

Wikipedia.org