Fetch your Sites Visitor's Location(Longitude & Lattitiude) using a simple javascript
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(function (position) {
myLatLng = new google.maps.LatLng(position.coords.latitude, position.coords.longitude);
alert(myLatLng )
},
function () {
alert('fallback');
});
}