diff --git a/www/map.js b/www/map.js
index 146d22e..076e8e4 100644
--- a/www/map.js
+++ b/www/map.js
@@ -158,6 +158,13 @@ $(document).ready(function() {
 			attribution: 'Tiles © Esri — Source: Esri, i-cubed, USDA, USGS, AEX, GeoEye, Getmapping, Aerogrid, IGN, IGP, UPR-EGP, and the GIS User Community'
 		}).addTo(map);
 		break;
+	case 'opentopo': // add OpenTopoMap tile layer https://opentopomap.org/
+		map = L.map('map', { zoomControl: false, worldCopyJump: true }).setView(config['map']['centerDefault'], config['map']['zoomDefault']);
+		L.tileLayer('https://{s}.tile.opentopomap.org/{z}/{x}/{y}.png',
+		{
+			attribution: 'Kartendaten: &copy; <a href="https://openstreetmap.org">OpenStreetMap</a> contributors, SRTM | Kartendarstellung: &copy; <a href="http://opentopomap.org/">OpenTopoMap</a> (<a href="https://creativecommons.org/licenses/by-sa/2.0/">CC-BY-SA</a>)'
+		}).addTo(map);
+		break;	
 	case 'osmde': // add OpenStreetMap.DE tile layer, default
 		null;
 	default:
diff --git a/www/map.js.en b/www/map.js.en
index 7e6070c..0b008e2 100644
--- a/www/map.js.en
+++ b/www/map.js.en
@@ -158,6 +158,13 @@ $(document).ready(function() {
 			attribution: 'Tiles &copy; Esri &mdash; Source: Esri, i-cubed, USDA, USGS, AEX, GeoEye, Getmapping, Aerogrid, IGN, IGP, UPR-EGP, and the GIS User Community'
 		}).addTo(map);
 		break;
+	case 'opentopo': // add OpenTopoMap tile layer https://opentopomap.org/
+		map = L.map('map', { zoomControl: false, worldCopyJump: true }).setView(config['map']['centerDefault'], config['map']['zoomDefault']);
+		L.tileLayer('https://{s}.tile.opentopomap.org/{z}/{x}/{y}.png',
+		{
+			attribution: 'Kartendaten: &copy; <a href="https://openstreetmap.org">OpenStreetMap</a> contributors, SRTM | Kartendarstellung: &copy; <a href="http://opentopomap.org/">OpenTopoMap</a> (<a href="https://creativecommons.org/licenses/by-sa/2.0/">CC-BY-SA</a>)'
+		}).addTo(map);
+		break;	
 	case 'osmde': // add OpenStreetMap.DE tile layer, default
 		null;
 	default: