diff --git a/apps/mobile/package.json b/apps/mobile/package.json
index 71a6df6..10fa9f0 100644
--- a/apps/mobile/package.json
+++ b/apps/mobile/package.json
@@ -28,6 +28,7 @@
     "expo-status-bar": "~3.0.9",
     "react": "19.1.0",
     "react-native": "0.81.5",
+    "react-native-maps": "^1.20.0",
     "react-native-safe-area-context": "~5.6.0",
     "react-native-screens": "~4.16.0",
     "react-native-svg": "^15.15.5"
diff --git a/apps/mobile/src/components/BikeSection.tsx b/apps/mobile/src/components/BikeSection.tsx
index 7ca8fc8..15d4586 100644
--- a/apps/mobile/src/components/BikeSection.tsx
+++ b/apps/mobile/src/components/BikeSection.tsx
@@ -1,9 +1,10 @@
 import { ActivityIndicator, StyleSheet, Text, View } from 'react-native';
 import { FontAwesomeIcon } from '@fortawesome/react-native-fontawesome';
-import { faClock, faRuler, faMap } from '@fortawesome/free-solid-svg-icons';
+import { faClock, faRuler } from '@fortawesome/free-solid-svg-icons';
 import { formatDuration, formatDistance } from '@timetoleave/core';
 import type { BikeRoute, Station } from '@timetoleave/core';
 import type { AppColors } from '../hooks/useColors';
+import { RouteMap } from './RouteMap';
 
 /** Props for the bike route information section shown on event detail. */
 interface Props {
@@ -14,7 +15,7 @@ interface Props {
 }
 
 /**
- * Displays cycling route duration, distance, and a map placeholder for the
+ * Displays cycling route duration, distance, and an interactive map for the
  * event's origin → destination leg. Shows contextual empty states when no
  * origin is set or no route is available.
  */
@@ -44,12 +45,9 @@ export function BikeSection({ bikeRoute, loading, origin, colors }: Props) {
             </View>
             <Text style={[styles.value, { color: colors.accent }]}>{formatDistance(bikeRoute.distance)}</Text>
           </View>
-          <View style={[styles.mapPlaceholder, { backgroundColor: colors.background, borderColor: colors.border }]}>
-            <View style={styles.mapTextRow}>
-              <FontAwesomeIcon icon={faMap} size={13} color={colors.subtext} />
-              <Text style={[styles.mapText, { color: colors.subtext }]}>Map (post-MVP)</Text>
-            </View>
-          </View>
+          {bikeRoute.geometry && (
+            <RouteMap geometry={bikeRoute.geometry} colors={colors} mode="bike" />
+          )}
         </View>
       ) : (
         <Text style={[styles.empty, { color: colors.subtext }]}>
@@ -71,14 +69,4 @@ const styles = StyleSheet.create({
   labelRow: { flexDirection: 'row', alignItems: 'center', gap: 6 },
   label: { fontSize: 15, fontWeight: '500' },
   value: { fontSize: 15, fontWeight: '600' },
-  mapTextRow: { flexDirection: 'row', alignItems: 'center', gap: 6 },
-  mapPlaceholder: {
-    marginTop: 10,
-    height: 100,
-    borderRadius: 8,
-    justifyContent: 'center',
-    alignItems: 'center',
-    borderWidth: 1,
-  },
-  mapText: { fontSize: 14 },
 });
diff --git a/apps/mobile/src/components/JourneyList.tsx b/apps/mobile/src/components/JourneyList.tsx
index e107d77..5309ee8 100644
--- a/apps/mobile/src/components/JourneyList.tsx
+++ b/apps/mobile/src/components/JourneyList.tsx
@@ -3,6 +3,7 @@ import { ActivityIndicator, StyleSheet, Text, TouchableOpacity, View } from 'rea
 import { formatDuration, formatDistance, rankJourneys } from '@timetoleave/core';
 import type { Journey, Station, WalkRoute } from '@timetoleave/core';
 import type { AppColors } from '../hooks/useColors';
+import { RouteMap } from './RouteMap';
 
 /** Props for the train journey list and optional final walk leg. */
 interface Props {
@@ -132,6 +133,9 @@ export function JourneyList({
             <Text style={[styles.walkLabel, { color: colors.text }]}>Distance</Text>
             <Text style={[styles.walkValue, { color: colors.accent }]}>{formatDistance(walkRoute.distance)}</Text>
           </View>
+          {walkRoute.geometry && (
+            <RouteMap geometry={walkRoute.geometry} colors={colors} mode="walk" />
+          )}
         </View>
       )}
 
diff --git a/apps/mobile/src/components/RouteMap.tsx b/apps/mobile/src/components/RouteMap.tsx
new file mode 100644
index 0000000..595365b
--- /dev/null
+++ b/apps/mobile/src/components/RouteMap.tsx
@@ -0,0 +1,85 @@
+import { useMemo } from 'react';
+import { StyleSheet, View } from 'react-native';
+import MapView, { Marker, Polyline } from 'react-native-maps';
+import { decodePolyline } from '../utils/polyline';
+import type { AppColors } from '../hooks/useColors';
+
+interface Props {
+  geometry: string;
+  colors: AppColors;
+  mode: 'bike' | 'walk';
+}
+
+function getRegionFromCoordinates(
+  coords: Array<{ latitude: number; longitude: number }>,
+) {
+  let minLat = Infinity;
+  let maxLat = -Infinity;
+  let minLng = Infinity;
+  let maxLng = -Infinity;
+
+  for (const c of coords) {
+    minLat = Math.min(minLat, c.latitude);
+    maxLat = Math.max(maxLat, c.latitude);
+    minLng = Math.min(minLng, c.longitude);
+    maxLng = Math.max(maxLng, c.longitude);
+  }
+
+  const latDelta = (maxLat - minLat) * 1.3; // 30 % padding
+  const lngDelta = (maxLng - minLng) * 1.3;
+
+  return {
+    latitude: (minLat + maxLat) / 2,
+    longitude: (minLng + maxLng) / 2,
+    latitudeDelta: Math.max(latDelta, 0.005),
+    longitudeDelta: Math.max(lngDelta, 0.005),
+  };
+}
+
+/**
+ * Renders an interactive map with the decoded route polyline and start/end
+ * markers. Automatically centres and zooms to fit the entire route.
+ */
+export function RouteMap({ geometry, colors, mode }: Props) {
+  const coords = useMemo(() => decodePolyline(geometry), [geometry]);
+
+  const region = useMemo(() => {
+    if (coords.length < 2) return null;
+    return getRegionFromCoordinates(coords);
+  }, [coords]);
+
+  if (!region || coords.length < 2) {
+    return null;
+  }
+
+  const strokeColor = mode === 'bike' ? colors.accent : colors.success;
+  const startCoord = coords[0];
+  const endCoord = coords[coords.length - 1];
+
+  return (
+    <View style={[styles.container, { borderColor: colors.border }]}>
+      <MapView style={styles.map} initialRegion={region} scrollEnabled={false} zoomEnabled={false} rotateEnabled={false} pitchEnabled={false}>
+        <Polyline
+          coordinates={coords}
+          strokeColor={strokeColor}
+          strokeWidth={4}
+        />
+        <Marker coordinate={startCoord} pinColor={colors.accent} />
+        <Marker coordinate={endCoord} pinColor={colors.success} />
+      </MapView>
+    </View>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: {
+    marginTop: 10,
+    height: 220,
+    borderRadius: 8,
+    overflow: 'hidden',
+    borderWidth: 1,
+  },
+  map: {
+    ...StyleSheet.absoluteFillObject,
+  },
+});
diff --git a/apps/mobile/src/utils/polyline.ts b/apps/mobile/src/utils/polyline.ts
new file mode 100644
index 0000000..fc47090
--- /dev/null
+++ b/apps/mobile/src/utils/polyline.ts
@@ -0,0 +1,46 @@
+/**
+ * Decode a Google polyline string into an array of { latitude, longitude } points.
+ *
+ * Based on the polyline algorithm:
+ * https://developers.google.com/maps/documentation/utilities/polylinealgorithm
+ */
+export function decodePolyline(encoded: string): Array<{ latitude: number; longitude: number }> {
+  const points: Array<{ latitude: number; longitude: number }> = [];
+  let index = 0;
+  let lat = 0;
+  let lng = 0;
+
+  while (index < encoded.length) {
+    let b;
+    let shift = 0;
+    let result = 0;
+
+    // Decode latitude
+    do {
+      b = encoded.charCodeAt(index++) - 63;
+      result |= (b & 0x1f) << shift;
+      shift += 5;
+    } while (b >= 0x20);
+    const dlat = (result & 1) !== 0 ? ~(result >> 1) : result >> 1;
+    lat += dlat;
+
+    shift = 0;
+    result = 0;
+
+    // Decode longitude
+    do {
+      b = encoded.charCodeAt(index++) - 63;
+      result |= (b & 0x1f) << shift;
+      shift += 5;
+    } while (b >= 0x20);
+    const dlng = (result & 1) !== 0 ? ~(result >> 1) : result >> 1;
+    lng += dlng;
+
+    points.push({
+      latitude: lat / 1e5,
+      longitude: lng / 1e5,
+    });
+  }
+
+  return points;
+}
diff --git a/apps/web/src/app/api/__tests__/bike-route.test.ts b/apps/web/src/app/api/__tests__/bike-route.test.ts
index 6eb5c35..4bafb8c 100644
--- a/apps/web/src/app/api/__tests__/bike-route.test.ts
+++ b/apps/web/src/app/api/__tests__/bike-route.test.ts
@@ -29,6 +29,7 @@ describe("api/bike-route/route", () => {
     mockGetBikeRoute.mockResolvedValue({
       distance: 1500,
       duration: 300,
+      geometry: "_p~iF~ps|U_ulLnnqC_mqNvxq`@",
       steps: [
         { name: "Start", distance: 100, duration: 10, instruction: "Go straight" },
         { name: "Turn left", distance: 200, duration: 20, instruction: "Turn left at the corner" },
@@ -45,6 +46,7 @@ describe("api/bike-route/route", () => {
     expect(data).toHaveProperty("distance");
     expect(data).toHaveProperty("duration");
     expect(data).toHaveProperty("steps");
+    expect(data).toHaveProperty("geometry");
   });
 
   it("should handle client error", async () => {
diff --git a/apps/web/src/app/api/__tests__/walk-route.test.ts b/apps/web/src/app/api/__tests__/walk-route.test.ts
index 6148ab0..1216699 100644
--- a/apps/web/src/app/api/__tests__/walk-route.test.ts
+++ b/apps/web/src/app/api/__tests__/walk-route.test.ts
@@ -29,6 +29,7 @@ describe("api/walk-route/route", () => {
     mockGetWalkRoute.mockResolvedValue({
       distance: 800,
       duration: 600,
+      geometry: "_p~iF~ps|U_ulLnnqC_mqNvxq`@",
       steps: [
         { name: "Start", distance: 50, duration: 40, instruction: "Head north" },
         { name: "Main St", distance: 150, duration: 120, instruction: "Turn right" },
@@ -45,6 +46,7 @@ describe("api/walk-route/route", () => {
     expect(data).toHaveProperty("distance");
     expect(data).toHaveProperty("duration");
     expect(data).toHaveProperty("steps");
+    expect(data).toHaveProperty("geometry");
   });
 
   it("should handle client error", async () => {
diff --git a/apps/web/src/lib/bike-routing-client.ts b/apps/web/src/lib/bike-routing-client.ts
index af2e318..80f3f5a 100644
--- a/apps/web/src/lib/bike-routing-client.ts
+++ b/apps/web/src/lib/bike-routing-client.ts
@@ -17,6 +17,7 @@ interface OsrmRoute {
   distance: number;
   duration: number;
   legs: Array<{ steps: OsrmStep[] }>;
+  geometry: string;
 }
 
 interface OsrmResponse {
@@ -66,7 +67,7 @@ export class BikeRoutingClient {
 
     const res = await this.client.get<OsrmResponse>(
       path,
-      { overview: "false", steps: "true" },
+      { overview: "full", steps: "true", geometries: "polyline" },
       {
         cacheKey,
         ttl: this.defaultTtlMs,
@@ -87,6 +88,7 @@ export class BikeRoutingClient {
       distance: route.distance,
       duration: route.duration,
       steps,
+      geometry: route.geometry,
     };
   }
 
diff --git a/apps/web/src/lib/walk-routing-client.ts b/apps/web/src/lib/walk-routing-client.ts
index 22c2b2a..1776b30 100644
--- a/apps/web/src/lib/walk-routing-client.ts
+++ b/apps/web/src/lib/walk-routing-client.ts
@@ -19,6 +19,7 @@ interface OsrmRoute {
   distance: number;
   duration: number;
   legs: Array<{ steps: OsrmStep[] }>;
+  geometry: string;
 }
 
 interface OsrmResponse {
@@ -68,7 +69,7 @@ export class WalkRoutingClient {
 
       const res = await this.client.get<OsrmResponse>(
         path,
-        { overview: "false", steps: "true" },
+        { overview: "full", steps: "true", geometries: "polyline" },
         {
           cacheKey,
           ttl: this.defaultTtlMs,
@@ -90,6 +91,7 @@ export class WalkRoutingClient {
         distance: route.distance,
         duration: Math.max(route.duration, walkingDuration),
         steps,
+        geometry: route.geometry,
       };
     }
 
diff --git a/package-lock.json b/package-lock.json
index b090112..6f5d63a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -11,6 +11,11 @@
         "apps/*",
         "packages/*"
       ],
+      "dependencies": {
+        "expo": "~54.0.34",
+        "react": "19.1.0",
+        "react-native": "0.81.5"
+      },
       "devDependencies": {
         "husky": "^9.1.7",
         "lint-staged": "^17.0.5"
@@ -35,6 +40,7 @@
         "expo-status-bar": "~3.0.9",
         "react": "19.1.0",
         "react-native": "0.81.5",
+        "react-native-maps": "^1.20.0",
         "react-native-safe-area-context": "~5.6.0",
         "react-native-screens": "~4.16.0",
         "react-native-svg": "^15.15.5"
@@ -5386,6 +5392,12 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@types/geojson": {
+      "version": "7946.0.16",
+      "resolved": "https://registry.npmjs.org/@types/geojson/-/geojson-7946.0.16.tgz",
+      "integrity": "sha512-6C8nqWur3j98U6+lXDfTUWIfgvZU+EumvpHKcYjujKH7woYyLj2sUmff0tRhrqM7BohUw7Pz3ZB1jj2gW9Fvmg==",
+      "license": "MIT"
+    },
     "node_modules/@types/graceful-fs": {
       "version": "4.1.9",
       "resolved": "https://registry.npmjs.org/@types/graceful-fs/-/graceful-fs-4.1.9.tgz",
@@ -15764,6 +15776,28 @@
         "react-native": "*"
       }
     },
+    "node_modules/react-native-maps": {
+      "version": "1.27.2",
+      "resolved": "https://registry.npmjs.org/react-native-maps/-/react-native-maps-1.27.2.tgz",
+      "integrity": "sha512-VKr+xZ2RZGHHJlY6KhlafvGSmK0dq/tUu5uhfJ7K9rwN5pUdubdugzMKGDU/16lXmQSg7xbClKhRctj3Pm5F5g==",
+      "license": "MIT",
+      "dependencies": {
+        "@types/geojson": "^7946.0.13"
+      },
+      "engines": {
+        "node": ">= 20.19.4"
+      },
+      "peerDependencies": {
+        "react": ">= 18.3.1",
+        "react-native": ">= 0.76.0",
+        "react-native-web": ">= 0.11"
+      },
+      "peerDependenciesMeta": {
+        "react-native-web": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/react-native-safe-area-context": {
       "version": "5.6.2",
       "resolved": "https://registry.npmjs.org/react-native-safe-area-context/-/react-native-safe-area-context-5.6.2.tgz",
@@ -18913,7 +18947,8 @@
         "@timetoleave/core": "*"
       },
       "devDependencies": {
-        "typescript": "^5"
+        "typescript": "^5",
+        "vitest": "^4.1.5"
       }
     },
     "packages/core": {
diff --git a/package.json b/package.json
index 4c2b5c2..33d140d 100644
--- a/package.json
+++ b/package.json
@@ -15,7 +15,9 @@
     "test": "npm run test -w apps/web && npm run test -w apps/mobile && npm run test -w packages/core && npm run test -w packages/api-client",
     "dev:mobile": "npm run start -w apps/mobile",
     "typecheck:mobile": "npm run typecheck -w apps/mobile",
-    "prepare": "husky"
+    "prepare": "husky",
+    "android": "expo run:android",
+    "ios": "expo run:ios"
   },
   "lint-staged": {
     "*.{ts,tsx}": [
@@ -31,5 +33,10 @@
   "devDependencies": {
     "husky": "^9.1.7",
     "lint-staged": "^17.0.5"
+  },
+  "dependencies": {
+    "expo": "~54.0.34",
+    "react": "19.1.0",
+    "react-native": "0.81.5"
   }
 }
diff --git a/packages/core/src/types.ts b/packages/core/src/types.ts
index 6d73cc9..6557cac 100644
--- a/packages/core/src/types.ts
+++ b/packages/core/src/types.ts
@@ -54,6 +54,8 @@ export interface BikeRoute {
   distance: number;
   duration: number;
   steps: BikeStep[];
+  /** Encoded polyline geometry (Google polyline format). */
+  geometry?: string;
 }
 
 /** Walking route from OSRM with turn-by-turn steps. */
@@ -61,6 +63,8 @@ export interface WalkRoute {
   distance: number;
   duration: number;
   steps: WalkStep[];
+  /** Encoded polyline geometry (Google polyline format). */
+  geometry?: string;
 }
 
 /** Walking step from OSRM route data. */