martyry vs nymphaeum

martyry

noun
  • A shrine at a site which "bears witness" to a crucial religious event not related to a tomb. 

  • A shrine in honor of a (usually religious, notably Christian) martyr, possibly at his grave. 

nymphaeum

noun
  • An ancient Greek or Roman shrine consecrated to water nymphs, often with a fountain. 

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