diff --git a/src/interact/drag.rs b/src/interact/drag.rs
index 0dc18b2..f757a31 100644
--- a/src/interact/drag.rs
+++ b/src/interact/drag.rs
@@ -10,7 +10,10 @@ use super::{
     stair_drag_at_pointer, text_at_pointer,
 };
 use crate::app::DungeonApp;
-use crate::layout::{blocked_room_cells, shortest_path_cells};
+use crate::layout::{
+    blocked_room_cells, is_cell_inside, is_marker_inside, is_room_inside, is_stair_inside,
+    shortest_path_cells,
+};
 use crate::ui::AddTool;
 use eframe::egui;
 use egui::{Color32, Stroke};
@@ -57,10 +60,70 @@ pub fn handle_drag(
         && let Some((room_idx, offset_x, offset_y)) = room_at_pointer(app, pointer_pos, geometry)
     {
         app.push_undo_snapshot();
+        let active_idx = app.settings.active_level_index;
+        let layout = &app.levels[active_idx];
+        let outer_room = &layout.rooms[room_idx];
+
+        let mut nested_rooms = Vec::new();
+        for (i, room) in layout.rooms.iter().enumerate() {
+            if i != room_idx && is_room_inside(room, outer_room) {
+                nested_rooms.push(i);
+            }
+        }
+
+        let mut nested_start_markers = Vec::new();
+        for (i, marker) in layout.start_markers.iter().enumerate() {
+            if is_marker_inside(marker, outer_room) {
+                nested_start_markers.push(i);
+            }
+        }
+
+        let mut nested_end_markers = Vec::new();
+        for (i, marker) in layout.end_markers.iter().enumerate() {
+            if is_marker_inside(marker, outer_room) {
+                nested_end_markers.push(i);
+            }
+        }
+
+        let mut nested_trap_markers = Vec::new();
+        for (i, marker) in layout.trap_markers.iter().enumerate() {
+            if is_marker_inside(marker, outer_room) {
+                nested_trap_markers.push(i);
+            }
+        }
+
+        let mut nested_monster_markers = Vec::new();
+        for (i, marker) in layout.monster_markers.iter().enumerate() {
+            if is_marker_inside(marker, outer_room) {
+                nested_monster_markers.push(i);
+            }
+        }
+
+        let mut nested_text_labels = Vec::new();
+        for (i, label) in layout.text_labels.iter().enumerate() {
+            if is_cell_inside(label.cell, outer_room) {
+                nested_text_labels.push(i);
+            }
+        }
+
+        let mut nested_stairs = Vec::new();
+        for (i, stair) in layout.stairs.iter().enumerate() {
+            if is_stair_inside(stair, outer_room) {
+                nested_stairs.push(i);
+            }
+        }
+
         app.drag_state = Some(DragState::Room(RoomDragState {
             room_idx,
             offset_x,
             offset_y,
+            nested_rooms,
+            nested_start_markers,
+            nested_end_markers,
+            nested_trap_markers,
+            nested_monster_markers,
+            nested_text_labels,
+            nested_stairs,
         }));
     }
 
@@ -118,9 +181,72 @@ pub fn drag_room_to_pointer(
         return;
     }
 
-    app.levels[app.settings.active_level_index].rooms[drag.room_idx].x = new_x;
-    app.levels[app.settings.active_level_index].rooms[drag.room_idx].y = new_y;
+    let delta_x = new_x as isize - old_x as isize;
+    let delta_y = new_y as isize - old_y as isize;
+
+    {
+        let level = &mut app.levels[app.settings.active_level_index];
+        level.rooms[drag.room_idx].x = new_x;
+        level.rooms[drag.room_idx].y = new_y;
+
+        for &idx in &drag.nested_rooms {
+            if idx < level.rooms.len() {
+                level.rooms[idx].x = (level.rooms[idx].x as isize + delta_x) as usize;
+                level.rooms[idx].y = (level.rooms[idx].y as isize + delta_y) as usize;
+            }
+        }
+        for &idx in &drag.nested_start_markers {
+            if idx < level.start_markers.len() {
+                level.start_markers[idx].cell.0 =
+                    (level.start_markers[idx].cell.0 as isize + delta_x) as usize;
+                level.start_markers[idx].cell.1 =
+                    (level.start_markers[idx].cell.1 as isize + delta_y) as usize;
+            }
+        }
+        for &idx in &drag.nested_end_markers {
+            if idx < level.end_markers.len() {
+                level.end_markers[idx].cell.0 =
+                    (level.end_markers[idx].cell.0 as isize + delta_x) as usize;
+                level.end_markers[idx].cell.1 =
+                    (level.end_markers[idx].cell.1 as isize + delta_y) as usize;
+            }
+        }
+        for &idx in &drag.nested_trap_markers {
+            if idx < level.trap_markers.len() {
+                level.trap_markers[idx].cell.0 =
+                    (level.trap_markers[idx].cell.0 as isize + delta_x) as usize;
+                level.trap_markers[idx].cell.1 =
+                    (level.trap_markers[idx].cell.1 as isize + delta_y) as usize;
+            }
+        }
+        for &idx in &drag.nested_monster_markers {
+            if idx < level.monster_markers.len() {
+                level.monster_markers[idx].cell.0 =
+                    (level.monster_markers[idx].cell.0 as isize + delta_x) as usize;
+                level.monster_markers[idx].cell.1 =
+                    (level.monster_markers[idx].cell.1 as isize + delta_y) as usize;
+            }
+        }
+        for &idx in &drag.nested_text_labels {
+            if idx < level.text_labels.len() {
+                level.text_labels[idx].cell.0 =
+                    (level.text_labels[idx].cell.0 as isize + delta_x) as usize;
+                level.text_labels[idx].cell.1 =
+                    (level.text_labels[idx].cell.1 as isize + delta_y) as usize;
+            }
+        }
+        for &idx in &drag.nested_stairs {
+            if idx < level.stairs.len() {
+                level.stairs[idx].cell.0 = (level.stairs[idx].cell.0 as isize + delta_x) as usize;
+                level.stairs[idx].cell.1 = (level.stairs[idx].cell.1 as isize + delta_y) as usize;
+            }
+        }
+    }
+
     reroute_corridors_for_room(app, drag.room_idx);
+    for &idx in &drag.nested_rooms {
+        reroute_corridors_for_room(app, idx);
+    }
     app.refresh_doors();
 }
 
diff --git a/src/interact/types.rs b/src/interact/types.rs
index 8801e58..906f518 100644
--- a/src/interact/types.rs
+++ b/src/interact/types.rs
@@ -11,6 +11,13 @@ pub struct RoomDragState {
     pub room_idx: usize,
     pub offset_x: f32,
     pub offset_y: f32,
+    pub nested_rooms: Vec<usize>,
+    pub nested_start_markers: Vec<usize>,
+    pub nested_end_markers: Vec<usize>,
+    pub nested_trap_markers: Vec<usize>,
+    pub nested_monster_markers: Vec<usize>,
+    pub nested_text_labels: Vec<usize>,
+    pub nested_stairs: Vec<usize>,
 }
 
 #[derive(Debug, Clone)]
diff --git a/src/layout/utils.rs b/src/layout/utils.rs
index b34c92c..f2ef51a 100644
--- a/src/layout/utils.rs
+++ b/src/layout/utils.rs
@@ -128,6 +128,38 @@ pub fn overlaps_with_padding(a: &Room, b: &Room, padding: usize) -> bool {
     a_left < b_right && a_right > b_left && a_top < b_bottom && a_bottom > b_top
 }
 
+// Test whether one room is completely inside another.
+pub fn is_room_inside(inner: &Room, outer: &Room) -> bool {
+    inner.x >= outer.x
+        && inner.x + inner.width <= outer.x + outer.width
+        && inner.y >= outer.y
+        && inner.y + inner.height <= outer.y + outer.height
+}
+
+// Test whether a cell is inside a room.
+pub fn is_cell_inside(cell: (usize, usize), room: &Room) -> bool {
+    cell.0 >= room.x
+        && cell.0 < room.x + room.width
+        && cell.1 >= room.y
+        && cell.1 < room.y + room.height
+}
+
+// Test whether an area marker is completely inside a room.
+pub fn is_marker_inside(marker: &crate::layout::AreaMarker, room: &Room) -> bool {
+    marker.cell.0 >= room.x
+        && marker.cell.0 + marker.size <= room.x + room.width
+        && marker.cell.1 >= room.y
+        && marker.cell.1 + marker.size <= room.y + room.height
+}
+
+// Test whether a staircase is completely inside a room.
+pub fn is_stair_inside(stair: &crate::layout::Staircase, room: &Room) -> bool {
+    stair.cell.0 >= room.x
+        && stair.cell.0 + stair.width <= room.x + room.width
+        && stair.cell.1 >= room.y
+        && stair.cell.1 + stair.height <= room.y + room.height
+}
+
 // Checks whether rects overlap.
 #[allow(clippy::too_many_arguments)]
 pub fn rects_overlap(