bell tower vs pier

bell tower

noun
  • A tower in which a bell (or set of bells) is hung; a belfry. 

pier

noun
  • A rectangular pillar, or similar structure, that supports an arch, wall or roof, or the hinges of a gate. 

  • A structure supporting the junction between two spans of a bridge. 

  • A similar structure, especially at a seaside resort, used to provide entertainment. 

  • A raised platform built from the shore out over water, supported on piles; used to secure, or provide access to shipping; a jetty. 

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