diff --git a/src/data_collection/city_registry.py b/src/data_collection/city_registry.py
index 8d86c9a0..ef145514 100644
--- a/src/data_collection/city_registry.py
+++ b/src/data_collection/city_registry.py
@@ -9,6 +9,7 @@ CITY_REGISTRY = {
         "icao": "LTAC",
         "tz_offset": 10800,
         "use_fahrenheit": False,
+        "is_major": False,
         "risk_level": "medium",
         "risk_emoji": "🟡",
         "airport_name": "Esenboğa 机场",
@@ -22,6 +23,7 @@ CITY_REGISTRY = {
         "icao": "EGLC",
         "tz_offset": 0,
         "use_fahrenheit": False,
+        "is_major": True,
         "risk_level": "low",
         "risk_emoji": "🟢",
         "airport_name": "London City 机场",
@@ -35,6 +37,7 @@ CITY_REGISTRY = {
         "icao": "LFPG",
         "tz_offset": 3600,
         "use_fahrenheit": False,
+        "is_major": True,
         "risk_level": "medium",
         "risk_emoji": "🟡",
         "airport_name": "Charles de Gaulle 机场",
@@ -48,6 +51,7 @@ CITY_REGISTRY = {
         "icao": "RKSI",
         "tz_offset": 32400,
         "use_fahrenheit": False,
+        "is_major": True,
         "risk_level": "high",
         "risk_emoji": "🔴",
         "airport_name": "仁川国际机场",
@@ -61,6 +65,7 @@ CITY_REGISTRY = {
         "icao": "CYYZ",
         "tz_offset": -18000,
         "use_fahrenheit": False,
+        "is_major": True,
         "risk_level": "low",
         "risk_emoji": "🟢",
         "airport_name": "Pearson 国际机场",
@@ -74,6 +79,7 @@ CITY_REGISTRY = {
         "icao": "SAEZ",
         "tz_offset": -10800,
         "use_fahrenheit": False,
+        "is_major": True,
         "risk_level": "medium",
         "risk_emoji": "🟡",
         "airport_name": "Ezeiza 国际机场",
@@ -87,6 +93,7 @@ CITY_REGISTRY = {
         "icao": "NZWN",
         "tz_offset": 46800,
         "use_fahrenheit": False,
+        "is_major": False,
         "risk_level": "low",
         "risk_emoji": "🟢",
         "airport_name": "惠灵顿国际机场",
@@ -100,6 +107,7 @@ CITY_REGISTRY = {
         "icao": "KLGA",
         "tz_offset": -18000,
         "use_fahrenheit": True,
+        "is_major": True,
         "risk_level": "low",
         "risk_emoji": "🟢",
         "airport_name": "LaGuardia 机场",
@@ -113,6 +121,7 @@ CITY_REGISTRY = {
         "icao": "KORD",
         "tz_offset": -21600,
         "use_fahrenheit": True,
+        "is_major": False,
         "risk_level": "high",
         "risk_emoji": "🔴",
         "airport_name": "O'Hare 国际机场",
@@ -126,6 +135,7 @@ CITY_REGISTRY = {
         "icao": "KDAL",
         "tz_offset": -21600,
         "use_fahrenheit": True,
+        "is_major": False,
         "risk_level": "medium",
         "risk_emoji": "🟡",
         "airport_name": "Dallas Love Field 机场",
@@ -139,6 +149,7 @@ CITY_REGISTRY = {
         "icao": "KMIA",
         "tz_offset": -18000,
         "use_fahrenheit": True,
+        "is_major": False,
         "risk_level": "low",
         "risk_emoji": "🟢",
         "airport_name": "Miami 国际机场",
@@ -152,6 +163,7 @@ CITY_REGISTRY = {
         "icao": "KATL",
         "tz_offset": -18000,
         "use_fahrenheit": True,
+        "is_major": False,
         "risk_level": "low",
         "risk_emoji": "🟢",
         "airport_name": "Hartsfield-Jackson 机场",
@@ -165,6 +177,7 @@ CITY_REGISTRY = {
         "icao": "KSEA",
         "tz_offset": -28800,
         "use_fahrenheit": True,
+        "is_major": False,
         "risk_level": "low",
         "risk_emoji": "🟢",
         "airport_name": "Sea-Tac 国际机场",
@@ -178,6 +191,7 @@ CITY_REGISTRY = {
         "icao": "VILK",
         "tz_offset": 19800,
         "use_fahrenheit": False,
+        "is_major": False,
         "risk_level": "medium",
         "risk_emoji": "🟡",
         "airport_name": "Chaudhary Charan Singh 国际机场",
@@ -191,6 +205,7 @@ CITY_REGISTRY = {
         "icao": "SBGR",
         "tz_offset": -10800,
         "use_fahrenheit": False,
+        "is_major": True,
         "risk_level": "high",
         "risk_emoji": "🔴",
         "airport_name": "São Paulo/Guarulhos 机场",
@@ -204,6 +219,7 @@ CITY_REGISTRY = {
         "icao": "EDDM",
         "tz_offset": 3600,
         "use_fahrenheit": False,
+        "is_major": False,
         "risk_level": "high",
         "risk_emoji": "🔴",
         "airport_name": "Munich 机场",
diff --git a/web/app.py b/web/app.py
index 1a66da78..3509952c 100644
--- a/web/app.py
+++ b/web/app.py
@@ -548,6 +548,7 @@ async def list_cities():
                 "airport": risk.get("airport_name", ""),
                 "icao": risk.get("icao", ""),
                 "temp_unit": "fahrenheit" if info["f"] else "celsius",
+                "is_major": CITY_REGISTRY.get(name, {}).get("is_major", True),
             }
         )
     return {"cities": out}
diff --git a/web/static/app.js b/web/static/app.js
index 3d6b137a..97c28cc3 100644
--- a/web/static/app.js
+++ b/web/static/app.js
@@ -71,6 +71,33 @@ function initMap() {
   map.on("click", () => {
     closePanel();
   });
+
+  // Handle zoom-based visibility for local stations and minor cities
+  map.on("zoomend", updateMapVisibility);
+}
+
+function updateMapVisibility() {
+  if (!map) return;
+  const zoom = map.getZoom();
+
+  // 1. Handle Nearby Individual Stations (very high zoom only)
+  // These are the "Ankara-style" local station markers
+  if (zoom < 7) {
+    if (map.hasLayer(nearbyLayerGroup)) map.removeLayer(nearbyLayerGroup);
+  } else {
+    if (!map.hasLayer(nearbyLayerGroup)) map.addLayer(nearbyLayerGroup);
+  }
+
+  // 2. Handle Primary City Markers (Major vs Minor)
+  Object.values(markers).forEach(({ marker, city }) => {
+    const isMajor = city.is_major !== false;
+    // Hide minor cities (like Ankara/Atlanta) when zoomed way out
+    if (zoom < 4 && !isMajor) {
+      if (map.hasLayer(marker)) map.removeLayer(marker);
+    } else {
+      if (!map.hasLayer(marker)) map.addLayer(marker);
+    }
+  });
 }
 
 // ──────────────────────────────────────────────────────────
@@ -109,6 +136,7 @@ function addCityMarkers(cities) {
   });
 
   document.getElementById("cityCount").textContent = cities.length;
+  updateMapVisibility();
 }
 
 function updateMarkerTemp(cityName, temp) {