JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://cdn.leafletjs.com/leaflet/v0.7.7/leaflet.css">
<script src="https://cdn.leafletjs.com/leaflet/v0.7.7/leaflet.js"></script>
<div id="map" style="width: 600px; height: 400px"></div>

JavaScript

var cities = new L.FeatureGroup();
cities.bindPopup("Nice little popup");

		L.marker([39.61, -105.02]).bindPopup('This is Littleton, CO.').addTo(cities),
		L.marker([39.74, -104.99]).bindPopup('This is Denver, CO.').addTo(cities),
		L.marker([39.73, -104.8]).bindPopup('This is Aurora, CO.').addTo(cities),
		L.marker([39.77, -105.23]).bindPopup('This is Golden, CO.').addTo(cities);


	    var mbAttr = 'Map data &copy; <a href="http://openstreetmap.org">OpenStreetMap</a> contributors, ' +
				'<a href="http://creativecommons.org/licenses/by-sa/2.0/">CC-BY-SA</a>, ' +
				'Imagery © <a href="http://mapbox.com">Mapbox</a>',
			mbUrl = 'https://api.tiles.mapbox.com/v4/{id}/{z}/{x}/{y}.png?access_token=pk.eyJ1IjoibWFwYm94IiwiYSI6IjZjNmRjNzk3ZmE2MTcwOTEwMGY0MzU3YjUzOWFmNWZhIn0.Y8bhBaUMqFiPrDRW9hieoQ';

	    var grayscale   = L.tileLayer(mbUrl, {id: 'mapbox.light', attribution: mbAttr}),
		    streets  = L.tileLayer(mbUrl, {id: 'mapbox.streets',   attribution: mbAttr});

		var map = L.map('map', {
			center: [39.73, -104.99],
			zoom: 10,
			layers: [grayscale, cities]
		});

		var baseLayers = {
			"Grayscale": grayscale,
			"Streets": streets
		};

		var overlays = {
			"Cities": cities
		};

		L.control.layers(baseLayers, overlays).addTo(map);