diff --git a/apps/api/src/characters/entities/character.entity.ts b/apps/api/src/characters/entities/character.entity.ts
new file mode 100644
index 0000000..f8ca986
--- /dev/null
+++ b/apps/api/src/characters/entities/character.entity.ts
@@ -0,0 +1,47 @@
+import {
+  Column,
+  CreateDateColumn,
+  Entity,
+  JoinColumn,
+  ManyToOne,
+  PrimaryGeneratedColumn,
+  UpdateDateColumn,
+} from 'typeorm';
+import { LocationDefinition } from '../../world/entities/location-definition.entity';
+
+@Entity({ name: 'characters' })
+export class Character {
+  @PrimaryGeneratedColumn('uuid', { name: 'id' })
+  id!: string;
+
+  @Column({ name: 'name', type: 'varchar', length: 150 })
+  name!: string;
+
+  @Column({ name: 'level', type: 'integer' })
+  level!: number;
+
+  @Column({ name: 'experience', type: 'integer' })
+  experience!: number;
+
+  @Column({ name: 'base_hp', type: 'integer' })
+  baseHp!: number;
+
+  @Column({ name: 'base_attack', type: 'integer' })
+  baseAttack!: number;
+
+  @Column({ name: 'current_hp', type: 'integer' })
+  currentHp!: number;
+
+  @Column({ name: 'current_location_id', type: 'uuid' })
+  currentLocationId!: string;
+
+  @CreateDateColumn({ name: 'created_at', type: 'timestamptz' })
+  createdAt!: Date;
+
+  @UpdateDateColumn({ name: 'updated_at', type: 'timestamptz' })
+  updatedAt!: Date;
+
+  @ManyToOne(() => LocationDefinition, (location) => location.characters)
+  @JoinColumn({ name: 'current_location_id' })
+  currentLocation!: LocationDefinition;
+}
diff --git a/apps/api/src/database/migrations/1787072400000-CreateVisibleVerticalSlice.ts b/apps/api/src/database/migrations/1787072400000-CreateVisibleVerticalSlice.ts
new file mode 100644
index 0000000..f9f884d
--- /dev/null
+++ b/apps/api/src/database/migrations/1787072400000-CreateVisibleVerticalSlice.ts
@@ -0,0 +1,112 @@
+import { MigrationInterface, QueryRunner } from 'typeorm';
+
+export class CreateVisibleVerticalSlice1787072400000 implements MigrationInterface {
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query('CREATE EXTENSION IF NOT EXISTS "uuid-ossp"');
+    await queryRunner.query(`CREATE TABLE "location_definitions" (
+      "id" uuid NOT NULL DEFAULT uuid_generate_v4(),
+      "key" character varying(100) NOT NULL,
+      "name" character varying(150) NOT NULL,
+      "description" text NOT NULL,
+      "region_key" character varying(100) NOT NULL,
+      "min_recommended_level" integer NOT NULL,
+      "max_recommended_level" integer NOT NULL,
+      "danger_level" integer NOT NULL,
+      "is_safe" boolean NOT NULL,
+      "hunting_enabled" boolean NOT NULL,
+      "artwork_path" character varying(255) NOT NULL,
+      "created_at" TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT now(),
+      "updated_at" TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT now(),
+      CONSTRAINT "PK_location_definitions" PRIMARY KEY ("id")
+    )`);
+    await queryRunner.query(
+      'CREATE UNIQUE INDEX "IDX_location_definitions_key" ON "location_definitions" ("key")',
+    );
+    await queryRunner.query(`CREATE TABLE "characters" (
+      "id" uuid NOT NULL DEFAULT uuid_generate_v4(),
+      "name" character varying(150) NOT NULL,
+      "level" integer NOT NULL,
+      "experience" integer NOT NULL,
+      "base_hp" integer NOT NULL,
+      "base_attack" integer NOT NULL,
+      "current_hp" integer NOT NULL,
+      "current_location_id" uuid NOT NULL,
+      "created_at" TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT now(),
+      "updated_at" TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT now(),
+      CONSTRAINT "PK_characters" PRIMARY KEY ("id"),
+      CONSTRAINT "FK_characters_current_location" FOREIGN KEY ("current_location_id") REFERENCES "location_definitions"("id") ON DELETE RESTRICT ON UPDATE NO ACTION
+    )`);
+    await queryRunner.query(
+      'CREATE INDEX "IDX_characters_current_location" ON "characters" ("current_location_id")',
+    );
+    await queryRunner.query(`CREATE TABLE "location_connections" (
+      "id" uuid NOT NULL DEFAULT uuid_generate_v4(),
+      "from_location_id" uuid NOT NULL,
+      "to_location_id" uuid NOT NULL,
+      "travel_duration_seconds" integer NOT NULL,
+      "ambush_chance" numeric(5,4) NOT NULL,
+      "enabled" boolean NOT NULL,
+      CONSTRAINT "PK_location_connections" PRIMARY KEY ("id"),
+      CONSTRAINT "FK_location_connections_from_location" FOREIGN KEY ("from_location_id") REFERENCES "location_definitions"("id") ON DELETE RESTRICT ON UPDATE NO ACTION,
+      CONSTRAINT "FK_location_connections_to_location" FOREIGN KEY ("to_location_id") REFERENCES "location_definitions"("id") ON DELETE RESTRICT ON UPDATE NO ACTION
+    )`);
+    await queryRunner.query(`CREATE UNIQUE INDEX "IDX_location_connection_direction"
+      ON "location_connections" ("from_location_id", "to_location_id")`);
+    await queryRunner.query(
+      'CREATE INDEX "IDX_location_connections_from_location" ON "location_connections" ("from_location_id")',
+    );
+    await queryRunner.query(
+      'CREATE INDEX "IDX_location_connections_to_location" ON "location_connections" ("to_location_id")',
+    );
+    await queryRunner.query(
+      "CREATE TYPE \"travel_status_enum\" AS ENUM ('TRAVELLING', 'COMPLETED')",
+    );
+    await queryRunner.query(`CREATE TABLE "travels" (
+      "id" uuid NOT NULL DEFAULT uuid_generate_v4(),
+      "character_id" uuid NOT NULL,
+      "origin_location_id" uuid NOT NULL,
+      "target_location_id" uuid NOT NULL,
+      "started_at" TIMESTAMP WITH TIME ZONE NOT NULL,
+      "arrives_at" TIMESTAMP WITH TIME ZONE NOT NULL,
+      "status" "travel_status_enum" NOT NULL,
+      "created_at" TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT now(),
+      CONSTRAINT "PK_travels" PRIMARY KEY ("id"),
+      CONSTRAINT "FK_travels_character" FOREIGN KEY ("character_id") REFERENCES "characters"("id") ON DELETE RESTRICT ON UPDATE NO ACTION,
+      CONSTRAINT "FK_travels_origin_location" FOREIGN KEY ("origin_location_id") REFERENCES "location_definitions"("id") ON DELETE RESTRICT ON UPDATE NO ACTION,
+      CONSTRAINT "FK_travels_target_location" FOREIGN KEY ("target_location_id") REFERENCES "location_definitions"("id") ON DELETE RESTRICT ON UPDATE NO ACTION
+    )`);
+    await queryRunner.query(
+      'CREATE INDEX "IDX_travels_character" ON "travels" ("character_id")',
+    );
+    await queryRunner.query(
+      'CREATE INDEX "IDX_travels_origin_location" ON "travels" ("origin_location_id")',
+    );
+    await queryRunner.query(
+      'CREATE INDEX "IDX_travels_target_location" ON "travels" ("target_location_id")',
+    );
+    await queryRunner.query(`CREATE UNIQUE INDEX "IDX_active_travel_per_character"
+      ON "travels" ("character_id")
+      WHERE "status" = 'TRAVELLING'`);
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query('DROP INDEX "IDX_active_travel_per_character"');
+    await queryRunner.query('DROP INDEX "IDX_travels_target_location"');
+    await queryRunner.query('DROP INDEX "IDX_travels_origin_location"');
+    await queryRunner.query('DROP INDEX "IDX_travels_character"');
+    await queryRunner.query('DROP TABLE "travels"');
+    await queryRunner.query(
+      'DROP INDEX "IDX_location_connections_to_location"',
+    );
+    await queryRunner.query(
+      'DROP INDEX "IDX_location_connections_from_location"',
+    );
+    await queryRunner.query('DROP INDEX "IDX_location_connection_direction"');
+    await queryRunner.query('DROP TABLE "location_connections"');
+    await queryRunner.query('DROP INDEX "IDX_characters_current_location"');
+    await queryRunner.query('DROP TABLE "characters"');
+    await queryRunner.query('DROP INDEX "IDX_location_definitions_key"');
+    await queryRunner.query('DROP TABLE "location_definitions"');
+    await queryRunner.query('DROP TYPE "travel_status_enum"');
+  }
+}
diff --git a/apps/api/src/database/migrations/visible-vertical-slice.migration.spec.ts b/apps/api/src/database/migrations/visible-vertical-slice.migration.spec.ts
new file mode 100644
index 0000000..08c2f88
--- /dev/null
+++ b/apps/api/src/database/migrations/visible-vertical-slice.migration.spec.ts
@@ -0,0 +1,67 @@
+import 'reflect-metadata';
+import { readFileSync } from 'node:fs';
+import { join } from 'node:path';
+import { getMetadataArgsStorage } from 'typeorm';
+import { Character } from '../../characters/entities/character.entity';
+import { Travel } from '../../travel/entities/travel.entity';
+import { LocationConnection } from '../../world/entities/location-connection.entity';
+import { LocationDefinition } from '../../world/entities/location-definition.entity';
+
+describe('visible vertical slice schema', () => {
+  it('maps the location key and relationship foreign keys explicitly', () => {
+    const metadata = getMetadataArgsStorage();
+    const locationIndex = metadata.indices.find((index) => {
+      const metadataIndex = index as typeof index & {
+        options?: { unique?: boolean };
+        unique?: boolean;
+      };
+
+      return (
+        index.target === LocationDefinition &&
+        index.columns?.includes('key') &&
+        (metadataIndex.options?.unique ?? metadataIndex.unique) === true
+      );
+    });
+
+    expect(locationIndex).toBeDefined();
+
+    const joinColumns = metadata.joinColumns
+      .filter((joinColumn) =>
+        [Character, LocationConnection, Travel].includes(
+          joinColumn.target as typeof Character,
+        ),
+      )
+      .map((joinColumn) => joinColumn.name);
+
+    expect(joinColumns).toEqual(
+      expect.arrayContaining([
+        'current_location_id',
+        'from_location_id',
+        'to_location_id',
+        'character_id',
+        'origin_location_id',
+        'target_location_id',
+      ]),
+    );
+  });
+
+  it('creates the complete schema with explicit reversible SQL', () => {
+    const migrationText = readFileSync(
+      join(__dirname, '1787072400000-CreateVisibleVerticalSlice.ts'),
+      'utf8',
+    );
+
+    expect(migrationText).toContain('CREATE TABLE "location_definitions"');
+    expect(migrationText).toContain('CREATE TABLE "characters"');
+    expect(migrationText).toContain('CREATE TABLE "location_connections"');
+    expect(migrationText).toContain('CREATE TABLE "travels"');
+    expect(migrationText).toContain(
+      'CREATE UNIQUE INDEX "IDX_location_connection_direction"',
+    );
+    expect(migrationText).toContain(
+      'CREATE UNIQUE INDEX "IDX_active_travel_per_character"',
+    );
+    expect(migrationText).toContain('DROP TYPE "travel_status_enum"');
+    expect(migrationText).not.toContain('synchronize');
+  });
+});
diff --git a/apps/api/src/travel/entities/travel.entity.ts b/apps/api/src/travel/entities/travel.entity.ts
new file mode 100644
index 0000000..1029f3d
--- /dev/null
+++ b/apps/api/src/travel/entities/travel.entity.ts
@@ -0,0 +1,55 @@
+import {
+  Column,
+  CreateDateColumn,
+  Entity,
+  JoinColumn,
+  ManyToOne,
+  PrimaryGeneratedColumn,
+} from 'typeorm';
+import { Character } from '../../characters/entities/character.entity';
+import { LocationDefinition } from '../../world/entities/location-definition.entity';
+import { TravelStatus } from '../travel-status.enum';
+
+@Entity({ name: 'travels' })
+export class Travel {
+  @PrimaryGeneratedColumn('uuid', { name: 'id' })
+  id!: string;
+
+  @Column({ name: 'character_id', type: 'uuid' })
+  characterId!: string;
+
+  @Column({ name: 'origin_location_id', type: 'uuid' })
+  originLocationId!: string;
+
+  @Column({ name: 'target_location_id', type: 'uuid' })
+  targetLocationId!: string;
+
+  @Column({ name: 'started_at', type: 'timestamptz' })
+  startedAt!: Date;
+
+  @Column({ name: 'arrives_at', type: 'timestamptz' })
+  arrivesAt!: Date;
+
+  @Column({
+    name: 'status',
+    type: 'enum',
+    enum: TravelStatus,
+    enumName: 'travel_status_enum',
+  })
+  status!: TravelStatus;
+
+  @CreateDateColumn({ name: 'created_at', type: 'timestamptz' })
+  createdAt!: Date;
+
+  @ManyToOne(() => Character)
+  @JoinColumn({ name: 'character_id' })
+  character!: Character;
+
+  @ManyToOne(() => LocationDefinition)
+  @JoinColumn({ name: 'origin_location_id' })
+  originLocation!: LocationDefinition;
+
+  @ManyToOne(() => LocationDefinition)
+  @JoinColumn({ name: 'target_location_id' })
+  targetLocation!: LocationDefinition;
+}
diff --git a/apps/api/src/travel/travel-status.enum.ts b/apps/api/src/travel/travel-status.enum.ts
new file mode 100644
index 0000000..1f5c087
--- /dev/null
+++ b/apps/api/src/travel/travel-status.enum.ts
@@ -0,0 +1,4 @@
+export enum TravelStatus {
+  TRAVELLING = 'TRAVELLING',
+  COMPLETED = 'COMPLETED',
+}
diff --git a/apps/api/src/world/entities/location-connection.entity.ts b/apps/api/src/world/entities/location-connection.entity.ts
new file mode 100644
index 0000000..a2432b6
--- /dev/null
+++ b/apps/api/src/world/entities/location-connection.entity.ts
@@ -0,0 +1,51 @@
+import {
+  Column,
+  Entity,
+  Index,
+  JoinColumn,
+  ManyToOne,
+  PrimaryGeneratedColumn,
+} from 'typeorm';
+import { LocationDefinition } from './location-definition.entity';
+
+@Entity({ name: 'location_connections' })
+@Index(
+  'IDX_location_connection_direction',
+  ['fromLocationId', 'toLocationId'],
+  {
+    unique: true,
+  },
+)
+export class LocationConnection {
+  @PrimaryGeneratedColumn('uuid', { name: 'id' })
+  id!: string;
+
+  @Column({ name: 'from_location_id', type: 'uuid' })
+  fromLocationId!: string;
+
+  @Column({ name: 'to_location_id', type: 'uuid' })
+  toLocationId!: string;
+
+  @Column({ name: 'travel_duration_seconds', type: 'integer' })
+  travelDurationSeconds!: number;
+
+  @Column({ name: 'ambush_chance', type: 'numeric', precision: 5, scale: 4 })
+  ambushChance!: string;
+
+  @Column({ name: 'enabled', type: 'boolean' })
+  enabled!: boolean;
+
+  @ManyToOne(
+    () => LocationDefinition,
+    (location) => location.outgoingConnections,
+  )
+  @JoinColumn({ name: 'from_location_id' })
+  fromLocation!: LocationDefinition;
+
+  @ManyToOne(
+    () => LocationDefinition,
+    (location) => location.incomingConnections,
+  )
+  @JoinColumn({ name: 'to_location_id' })
+  toLocation!: LocationDefinition;
+}
diff --git a/apps/api/src/world/entities/location-definition.entity.ts b/apps/api/src/world/entities/location-definition.entity.ts
new file mode 100644
index 0000000..b6e86a2
--- /dev/null
+++ b/apps/api/src/world/entities/location-definition.entity.ts
@@ -0,0 +1,63 @@
+import {
+  Column,
+  CreateDateColumn,
+  Entity,
+  Index,
+  OneToMany,
+  PrimaryGeneratedColumn,
+  UpdateDateColumn,
+} from 'typeorm';
+import { Character } from '../../characters/entities/character.entity';
+import { LocationConnection } from './location-connection.entity';
+
+@Entity({ name: 'location_definitions' })
+@Index('IDX_location_definitions_key', ['key'], { unique: true })
+export class LocationDefinition {
+  @PrimaryGeneratedColumn('uuid', { name: 'id' })
+  id!: string;
+
+  @Column({ name: 'key', type: 'varchar', length: 100 })
+  key!: string;
+
+  @Column({ name: 'name', type: 'varchar', length: 150 })
+  name!: string;
+
+  @Column({ name: 'description', type: 'text' })
+  description!: string;
+
+  @Column({ name: 'region_key', type: 'varchar', length: 100 })
+  regionKey!: string;
+
+  @Column({ name: 'min_recommended_level', type: 'integer' })
+  minRecommendedLevel!: number;
+
+  @Column({ name: 'max_recommended_level', type: 'integer' })
+  maxRecommendedLevel!: number;
+
+  @Column({ name: 'danger_level', type: 'integer' })
+  dangerLevel!: number;
+
+  @Column({ name: 'is_safe', type: 'boolean' })
+  isSafe!: boolean;
+
+  @Column({ name: 'hunting_enabled', type: 'boolean' })
+  huntingEnabled!: boolean;
+
+  @Column({ name: 'artwork_path', type: 'varchar', length: 255 })
+  artworkPath!: string;
+
+  @CreateDateColumn({ name: 'created_at', type: 'timestamptz' })
+  createdAt!: Date;
+
+  @UpdateDateColumn({ name: 'updated_at', type: 'timestamptz' })
+  updatedAt!: Date;
+
+  @OneToMany(() => Character, (character) => character.currentLocation)
+  characters!: Character[];
+
+  @OneToMany(() => LocationConnection, (connection) => connection.fromLocation)
+  outgoingConnections!: LocationConnection[];
+
+  @OneToMany(() => LocationConnection, (connection) => connection.toLocation)
+  incomingConnections!: LocationConnection[];
+}