// Where you want to render the map.
var element = document.getElementById('osm-map');
// Height has to be set. You can do this in CSS too.
element.style = 'height:300px;';
// Create Leaflet map on map element.
var map = L.map(element);
// Add OSM tile leayer to the Leaflet map.
L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
attribution: '© OpenStreetMap contributors'
}).addTo(map);
// Target's GPS coordinates.
var target = L.latLng('47.50737', '19.04611');
// Set map's center to target with zoom 14.
map.setView(target, 14);
// Place a marker on the same location.
L.marker(target).addTo(map);