Where is this Rails file stored? db/development.sqlite3

I'm trying to find the sqlite database file that rails creates.

Sorry if this is a dumb question but which folder is this file stored in?

I've looked in all of the folders in my Rails project and can't find it.

My database.yml:

   development:
      adapter: sqlite3
      database: db/development.sqlite3
      pool: 5
      timeout: 5000