Claastra or Claustra: How To spell?

The word Claastra is misspelled against Claustra, which is plural of "Claustrum"

Word contains consecutive vowels 'AU' in between alphabets cl & stra is misspelled as 'AA'
Wrong Spelling: cl-aa-stra
Correct Spelling: cl-au-stra
Browse incorrect spellings of Claustra to spell it good.