diff --git a/app.js b/app.js
index 67dfc65..904114f 100644
--- a/app.js
+++ b/app.js
@@ -158,6 +158,7 @@ function addSightMarker(sight, number) {
 // Create popup content for markers
 function createPopupContent(sight) {
   const icon = categoryIcons[sight.category] || "📍";
+  const isSelected = selectedSights.has(sight.id);
   return `
     <div class="popup-content">
       <h4>${icon} ${sight.name}</h4>
@@ -165,6 +166,10 @@ function createPopupContent(sight) {
       <p><strong>Admission:</strong> ${sight.admission}</p>
       <p><strong>Hours:</strong> ${sight.hours}</p>
       <p><strong>Duration:</strong> ${sight.visit_duration}</p>
+      <label class="checkbox-wrapper" style="margin: 8px 0; display: block;">
+        <input type="checkbox" ${isSelected ? 'checked' : ''} onchange="toggleSightSelection(${sight.id})">
+        <span>Add to my route</span>
+      </label>
       <button onclick="openSightModal(${sight.id})" class="btn btn--primary btn--sm">More Details</button>
     </div>
   `;
@@ -278,7 +283,13 @@ function toggleSightSelection(sightId) {
   } else {
     selectedSights.add(sightId);
   }
-  
+
+  // Update the popup content for this sight's marker
+  const marker = markers.find(m => m.sightData && m.sightData.id === sightId);
+  if (marker) {
+    marker.setPopupContent(createPopupContent(marker.sightData));
+  }
+
   updateRouteDisplay();
   renderSightsList(getCurrentFilter(), getCurrentSearch());
 }