JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://cdn.leafletjs.com/leaflet-0.6.4/leaflet.js"></script>
<link rel="stylesheet" href="http://cdn.leafletjs.com/leaflet-0.6.4/leaflet.css">
<div id="map"></div>

CSS

#map { height: 400px; }

JavaScript

var map = L.map('map').setView([51.505, -0.09], 10);
L.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
    attribution: 'Map data &copy; <a href="http://openstreetmap.org">OpenStreetMap</a> ',
    maxZoom: 18
}).addTo(map);

var icon_normal = new L.icon({
    iconUrl: 'http://cdn.leafletjs.com/leaflet-0.6.4/images/marker-icon.png',
    iconAnchor: [0, 0],
    popupAnchor: [100, 100]
});

var marker = new L.Marker([51.505, -0.09], {
    icon: icon_normal
});

map.addLayer(marker);
var popup = L.popup()
    .setContent('<p>Hello world!<br />This is a nice popup.</p>');
marker.bindPopup(popup).openPopup();