diff --git a/src/core/execute.rs b/src/core/execute.rs
index f8825e7d..d7de4a07 100644
--- a/src/core/execute.rs
+++ b/src/core/execute.rs
@@ -2,7 +2,7 @@ use std::collections::{HashMap, VecDeque};
 use std::iter::FromIterator;
 use rand::{thread_rng, Rng};
 use core::map::PosHex;
-use core::{self, Moves, ObjId, PlayerId, State};
+use core::{self, Moves, ObjId, PlayerId, State, TileType};
 use core::command;
 use core::component::{self, Component};
 use core::command::Command;
@@ -295,6 +295,16 @@ fn random_free_sector_pos(state: &State, player_id: PlayerId) -> Option<PosHex>
     None
 }
 
+pub fn create_terrain(state: &mut State) {
+    for _ in 0..15 {
+        let pos = match random_free_pos(state) {
+            Some(pos) => pos,
+            None => continue,
+        };
+        state.map.set_tile(pos, TileType::Rocks);
+    }
+}
+
 // TODO: improve the API
 pub fn create_objects<F>(state: &mut State, cb: &mut F)
 where
diff --git a/src/core/mod.rs b/src/core/mod.rs
index f75945c8..b1d1ce66 100644
--- a/src/core/mod.rs
+++ b/src/core/mod.rs
@@ -42,13 +42,13 @@ pub struct Jokers(pub i32);
 
 #[derive(Clone, Copy, Debug)]
 pub enum TileType {
-    Floor,
-    Lava,
+    Plain,
+    Rocks,
 }
 
 impl Default for TileType {
     fn default() -> Self {
-        TileType::Floor
+        TileType::Plain
     }
 }
 
@@ -76,13 +76,8 @@ pub struct State {
 impl State {
     pub fn new(prototypes: Prototypes) -> Self {
         let radius = map::Distance(5); // TODO: pass `Options` struct
-        let mut map = HexMap::new(radius);
-        {
-            // TODO: load\generate maps
-            map.set_tile(PosHex { q: 0, r: 0 }, TileType::Lava);
-        }
         Self {
-            map,
+            map: HexMap::new(radius),
             player_id: PlayerId(0),
             players_count: 2, // TODO: Read from the `Options` struct
             parts: Parts::new(),
diff --git a/src/core/movement.rs b/src/core/movement.rs
index 61fc78f4..5f3251a1 100644
--- a/src/core/movement.rs
+++ b/src/core/movement.rs
@@ -39,8 +39,8 @@ pub fn max_cost() -> MovePoints {
 
 pub fn tile_cost(state: &State, _: ObjId, _: PosHex, pos: PosHex) -> MovePoints {
     match state.map().tile(pos) {
-        TileType::Floor => MovePoints(1),
-        TileType::Lava => MovePoints(3),
+        TileType::Plain => MovePoints(1),
+        TileType::Rocks => MovePoints(3),
     }
 }
 
diff --git a/src/screen/game.rs b/src/screen/game.rs
index 1cbae050..4e19824d 100644
--- a/src/screen/game.rs
+++ b/src/screen/game.rs
@@ -31,8 +31,8 @@ fn make_action_show_tile(
     let screen_pos = map::hex_to_point(view.tile_size(), at);
     let mut sprite = Sprite::from_path(context, "tile.png", view.tile_size() * 2.0);
     match state.map().tile(at) {
-        TileType::Floor => sprite.set_color([1.0, 1.0, 1.0, 1.0]),
-        TileType::Lava => sprite.set_color([1.0, 0.7, 0.7, 1.0]),
+        TileType::Plain => sprite.set_color([1.0, 1.0, 1.0, 1.0]),
+        TileType::Rocks => sprite.set_color([0.7, 0.7, 0.7, 1.0]),
     }
     sprite.set_pos(screen_pos);
     Box::new(action::Show::new(&view.layers().bg, &sprite))
@@ -135,6 +135,7 @@ fn build_gui(context: &mut Context) -> Gui<GuiCommand> {
 
 fn prepare_map_and_state(context: &mut Context, state: &mut State, view: &mut GameView) {
     let mut actions = Vec::new();
+    execute::create_terrain(state);
     actions.push(make_action_create_map(state, view, context));
     execute::create_objects(state, &mut |state, event, phase| {
         let action = visualize::visualize(state, view, context, event, phase);