Castelation or Castellation: How To spell?
The word Castelation is misspelled against Castellation, a noun meaning "The act of making into a castle."
Castellation has double "ll" is mispronounced as "l"Remember double 'LL' in between the strings caste & ation which should not be misspelled with single 'L'
Wrong Spelling:  caste-l-ation  Correct Spelling:  caste-ll-ation 
Find more incorrect spellings of Castellation to spell right way.