Google maps

tutorial: https://developers.google.com/maps/tutorials/fundamentals/adding-a-google-map

HTML

<script src="https://maps.googleapis.com/maps/api/js?sensor=false"></script>
<div id="map-canvas"></div>

CSS

#map-canvas {
    height: 300px;
    width: 600px;
    background-color: #CCC;
}

JavaScript

function map_init() {
				var defaultZoom = 17;
				var allMarkers = new Array();
				var svgSource = '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 150" ><path class="st0" fill="#FFFFFF" d="M50,145.5C40.6,131.6,2.5,73.4,2.5,50C2.5,23.8,23.8,2.5,50,2.5S97.5,23.8,97.5,50C97.5,73.4,59.4,131.6,50,145.5z" /><path class="st1" fill="#000000" d="m50 5c24.8 0 45 20.2 45 45 0 19.5-29.4 67.7-45 91.1-15.6-23.4-45-71.6-45-91.1 0-24.8 20.2-45 45-45m0-5c-27.6 0-50 22.4-50 50s50 100 50 100 50-72.4 50-100-22.4-50-50-50z" /><circle class="st2" fill="#ffbf00" cx="50" cy="50" r="27.5" /><path d="m50 25c13.8 0 25 11.2 25 25s-11.2 25-25 25-25-11.2-25-25 11.2-25 25-25m0-5c-16.6 0-30 13.4-30 30s13.4 30 30 30 30-13.4 30-30-13.4-30-30-30z" /></svg>';
				var mapOptions = {
					zoom: defaultZoom,
					mapTypeId: google.maps.MapTypeId.ROADMAP
				};
				var map = new google.maps.Map(document.getElementById('map-canvas'),mapOptions);
				for (i = 0; i < 257; i++) {
						var ranLat = Math.ceil(Math.random() * 5) * (Math.round(Math.random()) ? 1 : -1)
						var ranLng = Math.ceil(Math.random() * 5) * (Math.round(Math.random()) ? 1 : -1)
						var myLatlng = new google.maps.LatLng(ranLat,ranLng);
						var marker = new google.maps.Marker({
							icon: {
								scaledSize: new google.maps.Size(36, 36), // scaled size
								origin: new google.maps.Point(0,0), // origin
								anchor: new google.maps.Point(18, 36), // anchor
								url: 'data:image/svg+xml;charset=utf-8,' + encodeURIComponent(svgSource)
							},
							position:myLatlng,
							map:map,
							draggable:false,
						});
						allMarkers.push(marker);
				}
				map_zoom();
				function map_zoom (){
					var bounds = new google.maps.LatLngBounds();
					for(i = 0;i < allMarkers.length;i++) {
						bounds.extend(allMarkers[i].getPosition());
					}
					map.setCenter(bounds.getCenter());
						map.fitBounds(bounds);
					var listener = google.maps.event.addListener(map, "idle", function() {...