breathtaking vs unbelievable

breathtaking

adj
  • Very surprising or shocking; to such a degree as to cause astonishment. 

  • stunningly beautiful; amazing 

unbelievable

adj
  • Amazing, incredible; so surprising it is almost unable to believe. 

  • Not to be believed. 

  • Implausible or improbable. 

How often have the words breathtaking and unbelievable occurred in a corpus of books? (source: Google Ngram Viewer )