place a marker where the last click was

app.py

@@ -261,12 +261,9 @@ def main():
     amsterdam_coords = [52.3676, 4.9041]
     m = folium.Map(location=amsterdam_coords, zoom_start=13)
 
-    # Add a marker for Amsterdam city center
-    folium.Marker(
-        amsterdam_coords,
-        popup="Amsterdam City Center",
-        icon=folium.Icon(color="red", icon="info-sign")
-    ).add_to(m)
+    # Create a LayerGroup for the marker
+    marker_group = folium.FeatureGroup(name="Marker")
+    m.add_child(marker_group)
 
     # Display the map and get clicked coordinates
     map_data = st_folium(m, height=400, width=700)
@@ -276,6 +273,14 @@ def main():
         lat = map_data['last_clicked']['lat']
         lng = map_data['last_clicked']['lng']
 
+        # Clear previous markers and add new one
+        marker_group.clear()
+        marker_group.add_child(folium.Marker(
+            [lat, lng],
+            popup=f"Selected Location\n{lat:.4f}, {lng:.4f}",
+            icon=folium.Icon(color="red", icon="info-sign")
+        ))
+
         st.write(f"Selected coordinates: {lat:.4f}, {lng:.4f}")
 
         # Get nearest Mapillary image