Castiel had a population (as of 2010) of 128. , 6.5% of the population was made up of foreign nationals. The age distribution, , in Castiel is; 24 children or 20.2% of the population are between 0 and 9 years old. 8 teenagers or 6.7% are 10 to 14, and 4 teenagers or 3.4% are 15 to 19. Of the adult population, 4 people or 3.4% of the population are between 20 and 29 years old. 26 people or 21.8% are 30 to 39, 18 people or 15.1% are 40 to 49, and 13 people or 10.9% are 50 to 59. The senior population distribution is 9 people or 7.6% of the population are between 60 and 69 years old, 8 people or 6.7% are 70 to 79, there are 5 people or 4.2% who are 80 to 89. In the
2007 federal election the most popular party was the
SVP which received 54.1% of the vote. The next three most popular parties were the
SP (23.9%), the
FDP (20.8%) and the
CVP (1.3%). ==Heritage sites of national significance==