base camp vs gatehouse

base camp

noun
  • An encampment used temporarily for storing supplies and preparing for a larger activity, such as mountain climbing or hunting. 

gatehouse

noun
  • A shelter for a gatekeeper. 

  • A lodge besides the entrance to an estate; often the residence of a gatekeeper; also a dwelling formerly used as such a residence. 

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