catacomb vs mausoleum

catacomb

noun
  • An underground system of tunnels and chambers with recesses for graves, used (in former times) as a cemetery; a tunnel system used for burying the dead, as in Paris or Ancient Rome. 

mausoleum

noun
  • A large stately tomb or a building housing such a tomb or several tombs. 

  • A gloomy, usually large room or building. 

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