title: How to fix "bad string" error in json?
body: <p>jsonlint.com throws the following error on my second line of code: "SyntaxError: Bad string on line 2"</p>
  
  <p>But no matter what string I replace my current one with, it keeps throwing that error. Is it referring to something else other than "1"?</p>
  
  <pre><code>{
    "1": [{
      "city": "Paris",
      "country": "France",
      "date": 2015,
      "sights": [{"Eiffel Tower", "Versailles"}]
    }],
    "2": [{
      "city": "Rome",
      "country": "Italy",
      "date": 2016,
      "sights": [{"Parthenon"}]
    }]
  }
  </code></pre>