observatory vs vantage

observatory

noun
  • A lookout (vantage point with a view of the surrounding area) 

  • A place where stars, planets and other celestial bodies are observed, usually through a telescope; also place for observing meteorological or other natural phenomena. 

vantage

noun
  • A place or position affording a good view; a vantage point. 

  • A superior or more favorable situation or opportunity; gain; profit; advantage. 

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