Tiled Layer

<style>
#map {
  height: 350px;
  position: relative;
  width: 100%;
}

</style>
<div id="map"></div>

<script>
var NPMap = {
  baseLayers: false,
  div: 'map',
  maxZoom: 13,
  overlays: [{
    attribution: '© <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors, © <a href="https://cartodb.com/attributions">CartoDB</a>',
    icon: 'street',
    name: 'CartoDB Dark Matter',
    retinaId: '@2x',
    type: 'tiled',
    url: 'https://cartodb-basemaps-{s}.global.ssl.fastly.net/dark_all/{z}/{x}/{y}{{retina}}.png'
  }]
};

(function () {
  var s = document.createElement('script');
  s.src = 'https://www.nps.gov/lib/npmap.js/4.0.0/npmap-bootstrap.js';
  document.body.appendChild(s);
})();

</script>