diff --git a/src/levels/l07_complex.rs b/src/levels/l07_complex.rs
new file mode 100644
index 0000000..5bb7280
--- /dev/null
+++ b/src/levels/l07_complex.rs
@@ -0,0 +1,142 @@
+//! Level 7 — complex data structures. The full map of a single floor.
+//!
+//! Paired design note: `l07.md`.
+
+use rand::seq::SliceRandom;
+use rand::{Rng, SeedableRng};
+use rand_chacha::ChaCha8Rng;
+use serde::Serialize;
+use serde_yaml::{Mapping, Sequence, Value};
+
+use crate::describe::Describer;
+
+use super::{Generated, Level};
+
+pub struct Complex;
+
+const EXITS: &[&str] = &["north", "south", "east", "west", "up", "down"];
+const CONTENTS: &[&str] = &[
+    "torch", "bench", "gold", "ruby", "scroll", "tome", "dagger", "shield",
+];
+const ROOMS: &[(&str, &str)] = &[
+    ("entrance", "hall"),
+    ("treasury", "vault"),
+    ("library", "study"),
+    ("kitchen", "scullery"),
+];
+
+#[derive(Serialize)]
+struct DescCtx {
+    floor: i64,
+    rooms: Vec<RoomDesc>,
+}
+
+#[derive(Serialize)]
+struct RoomDesc {
+    name: String,
+    kind: String,
+    locked: bool,
+    exits: Vec<String>,
+    contents: Vec<String>,
+}
+
+impl Level for Complex {
+    fn id(&self) -> u8 {
+        7
+    }
+
+    fn name(&self) -> &'static str {
+        "The Floor Map"
+    }
+
+    fn generate(&self, seed: u64) -> Generated {
+        let mut rng = ChaCha8Rng::seed_from_u64(seed ^ 0x0000_0000_0000_0007);
+        let floor = rng.gen_range(1..=5i64);
+        let chosen: Vec<&(&'static str, &'static str)> =
+            ROOMS.choose_multiple(&mut rng, 2).collect();
+
+        let mut rooms_map = Mapping::new();
+        let mut desc_rooms = Vec::new();
+        for (name, kind) in &chosen {
+            let exits_n = rng.gen_range(1..=3);
+            let exits: Vec<&'static str> =
+                EXITS.choose_multiple(&mut rng, exits_n).copied().collect();
+            let contents_n = rng.gen_range(1..=3);
+            let contents: Vec<&'static str> = CONTENTS
+                .choose_multiple(&mut rng, contents_n)
+                .copied()
+                .collect();
+            let locked = rng.gen_bool(0.5);
+
+            let mut room = Mapping::new();
+            room.insert(
+                Value::String("type".to_string()),
+                Value::String((*kind).to_string()),
+            );
+            room.insert(Value::String("locked".to_string()), Value::Bool(locked));
+            let exits_seq: Sequence = exits
+                .iter()
+                .map(|e| Value::String((*e).to_string()))
+                .collect();
+            let contents_seq: Sequence = contents
+                .iter()
+                .map(|c| Value::String((*c).to_string()))
+                .collect();
+            room.insert(
+                Value::String("exits".to_string()),
+                Value::Sequence(exits_seq),
+            );
+            room.insert(
+                Value::String("contents".to_string()),
+                Value::Sequence(contents_seq),
+            );
+            rooms_map.insert(Value::String((*name).to_string()), Value::Mapping(room));
+
+            desc_rooms.push(RoomDesc {
+                name: (*name).to_string(),
+                kind: (*kind).to_string(),
+                locked,
+                exits: exits.iter().map(|s| s.to_string()).collect(),
+                contents: contents.iter().map(|s| s.to_string()).collect(),
+            });
+        }
+
+        let mut top = Mapping::new();
+        top.insert(Value::String("floor".to_string()), Value::from(floor));
+        top.insert(
+            Value::String("rooms".to_string()),
+            Value::Mapping(rooms_map),
+        );
+
+        let target_yaml =
+            serde_yaml::to_string(&Value::Mapping(top)).expect("serialise mapping");
+
+        let mut d = Describer::new();
+        d.register(
+            "l07",
+            "Floor {{ floor }}.\n\
+             {% for r in rooms %}\n\
+             {{ r.name }} — a {{ r.kind }} (locked: {{ r.locked }})\n\
+             \texits:    {% for e in r.exits %}{{ e }}{% if not loop.last %}, {% endif %}{% endfor %}\n\
+             \tcontents: {% for c in r.contents %}{{ c }}{% if not loop.last %}, {% endif %}{% endfor %}\n\
+             {% endfor %}\n\
+             💡 Combine maps, lists, and scalars — `floor:` is an int, each room is a dict with two lists.",
+        )
+        .expect("register template");
+        let description = d
+            .render(
+                "l07",
+                &DescCtx {
+                    floor,
+                    rooms: desc_rooms,
+                },
+            )
+            .expect("render template");
+
+        Generated {
+            target_yaml,
+            description,
+            flavor: "🗺 The map of this floor is rich with detail.".to_string(),
+        }
+    }
+}
diff --git a/src/levels/mod.rs b/src/levels/mod.rs
index 0a04c8b..fa55f6d 100644
--- a/src/levels/mod.rs
+++ b/src/levels/mod.rs
@@ -16,6 +16,7 @@ pub mod l03_dict;
 pub mod l04_list;
 pub mod l05_dict_list;
 pub mod l06_anchors;
+pub mod l07_complex;
 
 use serde::{Deserialize, Serialize};