Google Maps Infoboxの画像は、画像ギャラリーのある別のInfoboxに表示されます

var locations = [
  ['<div class="header">Lower</div><img id="myImg" src="https://www.geocodezip.net/images/snow.png" alt="Snow" style="width:100%;max-width:300px"><div id="myModal" class="modal"><span class="close">&times;</span><img class="modal-content" id="img01"><div id="caption"></div>', 37.77, -122.43, 4],
];

function initMap() {
  var map = new google.maps.Map(
    document.getElementById('map'), {
      zoom: 14,
      center: {
        lat: 37.78,
        lng: -122.44
      }
    });

  var infowindow = new google.maps.InfoWindow();

  var marker, i;

  var markers = new Array();

  for (i = 0; i < locations.length; i++) {
    marker = new google.maps.Marker({
      position: new google.maps.LatLng(locations[i][1], locations[i][2]),
      map: map,
    });

    google.maps.event.addListener(marker, 'click', (function(marker, i) {
      return function() {
        infowindow.setContent(locations[i][0], locations[i][6]);
        google.maps.event.addListener(infowindow, 'domready', function() {
          // Get the modal
          var modal = document.getElementById("myModal");

          // Get the image and insert it inside the modal - use its "alt" text as a caption
          var img = document.getElementById("myImg");
          var modalImg = document.getElementById("img01");
          var captionText = document.getElementById("caption");
          img.onclick = function() {
            modal.style.display = "block";
            modalImg.src = this.src;
            captionText.innerHTML = this.alt;
          }

          // Get the <span> element that closes the modal
          var span = document.getElementsByClassName("close")[0];

          // When the user clicks on <span> (x), close the modal
          span.onclick = function() {
            modal.style.display = "none";
          }
        })

        infowindow.open(map, marker);
      };
    })(marker, i));
    markers.push(marker);
  }
}

html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

#map {
  height: 100%;
}

#content {
  text-align: center;
  display: block;
  position: absolute;
  bottom: -8px;
  left: -20px;
  background-color: white;
  z-index: 10001;
}

.gm-style .gm-style-iw-c {
  padding-top: 1vw !important;
  padding-left: 1vw !important;
  padding-right: 1vw !important;
  padding-bottom: 0.5vw !important;
  border-color: white;
  border-radius: 0px !important;
}

.gm-ui-hover-effect {
  width: 60px !important;
  height: 30px !important;
}

.gm-ui-hover-effect img {
  padding-top: 0.5vw;
  width: 30px !important;
  height: 30px !important;
}

#bodyContent img {
  text-align: center;
}

#bodyContent p {
  text-align: left;
}

.header {
  padding-right: 2vw;
  font-weight: 600;
  font-size: 26px;
  padding-bottom: 15px;
  font-family: "IMB Plex Sans", sans-serif;
}

#address {
  font-size: 16px;
  line-height: 5px;
  font-family: "IMB Plex Sans", sans-serif;
}

#address-2 {
  font-size: 16px;
  line-height: 5px;
  font-family: "IMB Plex Sans", sans-serif;
  padding-bottom: 29px;
}

#hours {
  font-size: 12px;
  line-height: 20px;
  font-family: "IMB Plex Sans", sans-serif;
}

.row {
  display: flex;
  padding: 0 0px;
}


/* Create four equal columns that sits next to each other */

.column {
  flex: 25%;
  max-width: 25%;
  padding-top: 36px;
  padding-bottom: 0px;
  padding-left: 0px;
  padding-right: 18px;
}

.column img {
  margin-top: 8px;
  vertical-align: middle;
  height: 85px;
}

#myImg {
  border-radius: 5px;
  cursor: pointer;
  transition: 0.3s;
}

#myImg:hover {
  opacity: 0.7;
}


/* The Modal (background) */

.modal {
  display: none;
  /* Hidden by default */
  position: fixed;
  /* Stay in place */
  z-index: 1;
  /* Sit on top */
  padding-top: 100px;
  /* Location of the box */
  left: 0;
  top: 0;
  width: 100%;
  /* Full width */
  height: 100%;
  /* Full height */
  overflow: auto;
  /* Enable scroll if needed */
  background-color: rgb(0, 0, 0);
  /* Fallback color */
  background-color: rgba(0, 0, 0, 0.9);
  /* Black w/ opacity */
}


/* Modal Content (Image) */

.modal-content {
  margin: auto;
  display: block;
  width: 80%;
  max-width: 700px;
}


/* Caption of Modal Image (Image Text) - Same Width as the Image */

#caption {
  margin: auto;
  display: block;
  width: 80%;
  max-width: 700px;
  text-align: center;
  color: #ccc;
  padding: 10px 0;
  height: 150px;
}


/* Add Animation - Zoom in the Modal */

.modal-content,
#caption {
  animation-name: zoom;
  animation-duration: 0.6s;
}

@keyframes zoom {
  from {
    transform: scale(0)
  }
  to {
    transform: scale(1)
  }
}


/* The Close Button */

.close {
  position: absolute;
  top: 15px;
  right: 35px;
  color: #f1f1f1;
  font-size: 40px;
  font-weight: bold;
  transition: 0.3s;
}

.close:hover,
.close:focus {
  color: #bbb;
  text-decoration: none;
  cursor: pointer;
}


/* 100% Image Width on Smaller Screens */

@media only screen and (max-width: 700px) {
  .modal-content {
    width: 100%;
  }
}

<!DOCTYPE html>
<html>

<head>
  <title>Vigor Locations</title>
  <meta name="viewport" content="initial-scale=1.0">
  <meta charset="utf-8">
</head>

<body>
  <div id="map"></div>
  <!--
   <script>
    </script>
    -->
  <script type="text/javascript" src="map_custom_2.js"></script>
  <script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyBQfkiMFrFWpGHmP7YMFtlfQM6YEDqslNU&callback=initMap" async defer></script>
</body>

</html>